1. Shower faucet outlet inner diameter is 1 inch, or 25mm, and is usually fitted with a DN25 valve (faucets installed directly are less common). For household use, a reducer is typically used to reduce the diameter to 4/15 (DN15) or 6/10 (DN20).
2. The standard mounting hole spacing is 150mm, referring to the center-to-center distance between the hot and cold water inlet pipes. Shower faucets usually come with an S-bend adapter, which can adjust for ±16mm of error.
3. The standard center-to-center distance between the hot and cold water inlets is 150mm. If there is a deviation in the center-to-center distance between the hot and cold water inlets on the wall, it can be adjusted during installation using an elbow adapter attached to the faucet.
