Praxis chainring 1x MTB 104BCD. The single chainring features WAVE technology. Because the teeth are aligned alternately left and right, this creates lateral tension on the chain, which ensures that the chain stays on the front chainring. The chainrings are made of 7075-T6 aluminum and are available in 30, 32, 34, and 36 teeth. 104BCD. Suitable for 10, 11, and 12-speed chains. The rear derailleur must be a clutch type, for example, Shimano Shadow or Sram Type 2. In rough terrain, or for safety, we recommend using a chain guide. NOTE: The 30-tooth version has M8 holes; the required bolt must have a minimum thread length of 7.5 mm.