The Trail Jersey T3 from Assos is the 3rd generation of their trail, which has been in a regular state of assessment and evolution through the company's experience and sponsorship of World Cup mountain bike athletes. The T3 is an evolved version of the Assos all-mountain jersey, which applies Assos engineering to pure trail riding, combining the breathability of road-race jerseys and the durability of dedicated off-road equipment. The design team took in the feedback and rethought the the TRAIL fit profile. The T3 evolution features a slightly roomier chest to better accommodate muscularity, lightweight compact protection pads and allows the rider movement with clothing when in or out of the saddle.

Fabric-wise, the full body of the jersey is built with Assos own Triangle textile. This fabric has lateral stretch for greater freedom of body movement and muscularity, with little vertical stretch. The UPF35 fabric is has a soft interior feel, breathes extremely well, and moves nicely with or without something like the Summer NS Skin Sleeveless Layer. The collar and sleeve hems get the Majestic textile which is even softer and eases moisture off the skin with zero irritation. The sleeves themselves aren't restrictive, but loose without being too billowy. The design team shifted the T3 series to sleeves from a Raglan cut to a set-in design to better map the body. That is only a real option with the greater freedom of the cut and freedom of movement but it does define the shoulders a little more in the way that many riders prefer. The cut is also a little longer than the previous generation Trail jersey, giving the rider more coverage even when moving at speed and with fluidity on the bike.