However, it should be noted that the Sigma bracket is divided into 2 contacts and 4 contacts, which are divided into wireless and wired, 2; The difference between the four kinds of contacts lies in whether it supports step frequency measurement. 800 does not support stepping frequency, so 800 can be used on any watch base.
Other brands don't know each other. But it can't be used with SIGMA stand, which has its own patent for rotating installation, and other watches can't be used either.