Stan's NoTubes Rim Arch MK4 Rim, 27.5" x 32 hole, Black (with Gray decals)Unleash trail ready performance and tubeless reliability with the Stan's NoTubes Arch MK4 rim, meticulously engineered to be a durable and lightweight foundation for your custom wheel build. The Stan's NoTubes Arch MK4 rim is a definitive solution for mountain bikers who demand a perfect balance of durability, low weight, and a seamless tubeless experience. The fourth generation of the legendary Arch, the MK4 features Stan's patented Bead Socket