PrimoChill LRT/FSX Tubing and Fittings Kit 3/8in.ID x 5/8in.OD


SKU: FLEXK58-CCN/AAvailability : In stock - In Boise, ID USAIn StockOut of stock

LRT/FSX KIT PrimoChill has you covered from the beginning of your build to the end. For the first time a complete bundle is available that harmoniously matches stunning compression fittings, a... Read more


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Select SX Style*: Candy Copper

  • Candy Copper
  • Yellow
  • UV Red
  • UV Pink
  • UV Orange
  • UV Green
  • TX Matte Silver
  • TX Matte Gun Metal
  • TX Matte Black
  • True Blue
  • Toxic Candy
  • Sky White
  • Sky Blue
  • Candy Gold
  • Candy Purple
  • Candy Red
  • Copper
  • Silver Nickel
  • Gold
  • Magenta
  • Razor Red
  • Satin Black
  • Dark Nickel
Out of stock

PrimoChill has you covered from the beginning of your build to the end. For the first time a complete bundle is available that harmoniously matches stunning compression fittings, a perfect tubing solution as well as a cleaning solution and a distilled water additive that ensures a clear, clean, and protected cooling loop!

PrimoFlex Advanced LRT Tubing has been designed, formulated, and manufactured for today’s evolving standards in the PC water cooling industry. Advanced LRT has been carefully formulated to perform in a wide range of closed loop cooling systems, creating the most compatible water cooling tubing ever created. Combine this with the FSX series nickel finish compression fittings and you are ready to liquid cool. Ten fittings are included to allow up to five 2 port devices to be integrated into your cooling system without any additional fittings needed.

PrimoChill’s proprietary blend of notably low durometer PVC and more rigid polymer resin provides PrimoFlex Advanced LRT with an unbeatable bend ratio and durability. PrimoFlex has been tested in exacting laboratory set-ups. This included tests with abrupt small radius bends and multiple directional change that resisted both twisting and collapse which allows for tighter bends eliminating kinking that can cause cooling failures and reduction in system performance.

Smooth inner walls improve closed loop sanitation. Advanced LRT smooth surface inhibits particulate gathering or entrapment onto the tubing wall. This reduces the potential of bacterial growth and contamination. With this technology, Advanced LRT will keep your system looking and feeling as clean as the day it was installed.

SysPrep & Liquid Utopia INCLUDED
Included in the kit package at no additional cost is a 15mL bottle of SysPrep – Cooling Loop Pre-Treatment as well as a 15mL bottle of Liquid Utopia. Any successful venture into water-cooling starts with a true cooling loop preparation which can only be achieved by using Sys Prep. It will “flush” your loop and its components of any debris left by the manufacturing processes of your reservoir, block, pump, or radiator, leaving your water cooling loop clean, clear, pristine and ready for any type of coolant. Once your LRT tubing is crystal clear the Liquid Utopia offers a full line of protection against algae and corrosion.

  • Trusted/Experienced Brand. PrimoFlex
  • Inner Wall Resilience
  • FDA Approved ingredients
  • ROHS Compliant PVC
  • Glass Like Transparency. Crystal Clear
  • DEHP Free and Phthalate Free
  • Environmentally Responsible, Safe, and Non Toxic Product
  • Superior UV Transmission
  • Industry Standard G 1/4in. threads
  • Nickel Plated Brass base
  • Diamond Knurl Cap
  • Tubing Inner Diameter (ID): 3/8in. ±.005
  • Tubing Outer Diameter (OD): 5/8in. ±.015
  • Tubing Wall Thickness: 1/8in
  • Fitting Size: 3/8in. x 5/8in.
  • Fitting Color: Over 30 to choose from
  • Tubing Color:Clear

  • This kit is designed to work with any G 1/4in. thread system.
Parts Included
  • PRIMOFLEX – 10ft (For a Cleaner Cooling Loop)
  • SYSPREP – 15ml (Cooling Loop Pre-Treatment)
  • UTOPIA – 15ml (Algae/Corrosion Protectant)
  • 10x FlexSX Fitting w/ O-ring

With the use of different components, materials, fluids, and flow rates, results may vary with the appearance of your tubing. Although Advanced LRT is designed to work with a large variety of cooling components, the use of alcohols, Ethylene Glycol and as well as any other harmful chemicals is strictly prohibited and will void your warranty. Tubing will stain if dyed coolants are used. Although aluminum is used for the outside compression ring, no aluminum comes in direct contact with the fluid so mix metal corrosion is not an issue

Not responsible for any hardware damage by or when using this product. Use at your own risk.

Customer Reviews

Based on 2 reviews
Emmanuel G.
Awesome stuff

Soft Tubing feels like great quality, pipe cutter is of great quality as well, easy to cut. The fittings are pretty awesome, they have a nice weight to them are very well powered coated and are easy to screw in.

Brandon B.
Good tubes

Been doing colored tubing for 10 years and was in kind of a rush to get new tubes and color wasn’t going to slow me down. What I really like here is they sold fittings with matching tube so you know there won’t be a sizing issue.

Tubes and fitting work great. No leaks.

After a while I kinda like the clear tubes. I can always add color to the liquid at a later time.

The sys prep included in the bundle did like magic for my system. All my old residue from the previous solid color came right off. I dunno how, I tried scrubbing my reservoir prior to with windex and nothing would get it off. The sys prep made everything crystal clear.

Shipping Policy:

We ship via USPS and Fed Ex. For international orders, we ship via Fed Ex. Air shipments will be delivered via the selected carrier on the regular business day scheduling. Unfortunately, we cannot ship out orders for specific Saturday deliveries. During peak season, carriers suspend their delivery guarantees, and delays are expected.

Same-Day Shipping:
We strive to ship out every order the same day if the order is placed by 2:00 pm MST. If not, the order will ship out the next business day. Orders with custom powder coating (SX Colors) can take up to 1-4 business days to coat, inspect and pack, so please be aware. Selecting an overnight shipping method or rush fee will not ensure that your order ships the same day and is not guaranteed.

Shipment Refusal:
If a shipped order is refused or returned undelivered, there will be a mandatory 20% restocking fee, a $20.00 Return Service Fee, and no refund on the shipping cost. Please be aware that refusal is significantly more expensive than using your own carrier and is NOT recommended. 

Damaged Items:
All packages are fully insured at no additional charge.

If you receive a damaged package, you must notify us within 48 hours of receipt. Sending back damaged merchandise voids the shipping insurance and no credit will be given. Damaged packages must be held for ten days with original packaging for carrier inspection. All packaging and packing materials must be kept for this inspection.

If your package is marked delivered and not received, be sure to get in touch with immediately for further assistance.

International Shipping:

For international customers, please reference this page for duties/tax information. 

Returns Policy for New Products:

RMA Number:
Returns will not be accepted without an RMA number provided by

Product Return:

Products returned for credit must be received within 30 days of the invoice, and a 15% restocking fee may apply. If 30 days have passed since your purchase, unfortunately, we can’t offer you a refund or exchange.

All returned items must be in like-new condition with all related parts, including screws, manuals, etc. If you have lost, thrown away, scratched, or opened sealed boxes or bags – a higher restocking fee may apply upwards of 50%. Products with a fluid run through them are subject to these higher restocking fees.

Only regular-priced items may be refunded, unfortunately, sale items cannot be refunded. This includes B-Stock and Used/Open Box Products.

If a customer is misleading about the defect and evidence of incorrect installation/use or tampering has occurred, the return my denied, and a higher restock fee may be assessed, or the return may be denied entirely. A qualified technician will test each returned product for defects. will not assess a restocking fee for defective products.

Return Shipping
Customers are responsible for ALL return shipping charges on merchandise for any reason. Unless otherwise noted, shipping on products and returns is non-refundable, and returning a product comes at the customer's expense. The customer will be responsible for paying for shipping products/orders back to For no reason, do we refund the outbound shipping cost.


Once an order is placed on our e-commerce website, it cannot be canceled or changed. This is because our fully automated systems immediately start processing the order, which cannot be stopped or reversed. Therefore, we advise customers to double-check their orders before making a purchase.

Additionally, we would like to emphasize that our e-commerce website ships 98.5% of orders on the same day they are placed by 2:00 pm MST. Allowing cancellations after an order is placed would significantly slow down our shipping process and potentially affect the delivery times for other customers.

We understand that it can be frustrating to be unable to cancel an order, but we ask for your understanding in this matter. By adhering to our cancellation policy, we can ensure that our automated systems and shipping processes continue running smoothly, allowing us to provide fast and efficient service to all our customers.

We understand that sometimes mistakes can happen, and customers may accidentally order the wrong item or change their minds about a purchase. In such cases, we suggest that customers consider our return policy instead.

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PrimoChill LRT/FSX Tubing and Fittings Kit 3/8in.ID x 5/8in.OD