The sprocket wheel basically ensures frictionless and lossless transmission of the drive to the round steel chain. The sprocket wheel alternately holds a stationary and a horizontal chain link. The standing chain link is free-standing, while the lying one is gripped. In principle, the more pockets there are, the less uneven running will occur during operation.

The X-Drive sprocket is an outstanding development from ASM. Here, both chain links are horizontal, which leads to significantly quieter operation by reducing the polygon effect. This sprocket can be installed in the OttO 1000 as well as in the UNO 500.