Flexible J Channel

Engineered To Be The Best Flexible J-Channel!

FleX-J, the flexible j-channel from Extrudex, boasts a unique design and material selection that sets it apart from the competition. The features of the Extrudex FleX-J make it the best option for the installation of round and arch top windows.

FleX-J is unique in that it offers a true 1” face, one of the largest available on the market today. Designed with a UV Protected, anti-microbial, and dual durometer materials, the Extrudex FleX-J is the most stable, extruded flexible j-channel on the market.

Superior Design

See why FLex-j is the superior j-channel on the market

Superior design. Our enhanced design feature extends the semi-rigid material partially up both the Face and Nail Fin ends, allowing the Extrudex FleX-J to hold its shape around the tightest radii, this reduces the possibility of deforming the 1″ Face during installation. With two available sizes – 3/4” and 1-1/8”– each piece of flexible j-channel provides the proper fit with siding, limiting the distortion associated with “one-size fits all” j-channels.

A Top that’s curled-over

A significant design aspect of flex-j

Another unique aspect of the FleX-J by Extrudex is its “curled-over” top on the Face side. This feature provides the same professional finish found with rigid j-channels The FleX-J also offers the longest nail fin (1.67”) available. The nailing fin is tapered, ensuring easy installation. Our flexible j-channel for vinyl siding can streamline installation times and provide long-lasting results. The FleX-J is pretreated with UV inhibitor and fungicide to ensure that the j-channel is long-lasting and continues to look good.

3/4” FleX-J Channel

1 1/8” FleX-J Channel

FleX-J Specs

Flex-J Shipping Information


Carton Size

Lineal Feet/Carton

Delivery Time
5 working days for stock items

Painesville, OH 44077

Flex-j Colors

meeting the needs of your project

We currently offer white, clay, sand, and light gray. Need to match a specific color? The FleX-J by Extrudex is paintable. Follow the below simple guidelines:

• Talk to a professional about pre-treatment of the FleX-J surface prior to paint application.
• Use a urethane or acrylic based paint  (Polane® 2-part system from Sherwin Williams.)


Installing For Curved Openings

 The Extrudex Flex-J helps simplify installations around curved windows such as round tops and half round windows. To install around the top of these types of windows, please download instructions in our installation manual.