The ZTR Arch is a light, stiff tubeless rim for "aggressive XC use". Lightweight at just 420g but super-stiff.

At 24.4mm it's a bit wider than your average rim, meaning you get a better tyre profile, improved stiffness and excellent strength.  The internal structure of the rim forms an arch (hence the name), massively increasing stiffness which means excellent resistance to bending and a nice strong wheel.

The rims need to be sealed with tape such as the 25mm Yellow spoke sealing tape to make them airtight and protect the rimstrip. You also need a Olympic rimstrip or Olympic valve for running them tubeless, or they can be run as normal rims with tubes.