Kohler K-8013 Guía De Instalación Y Cuidado página 7

Adapter
6. Install the Adapter
Install the adapter to the pipe nipple using a socket wrench with
extension, 7/16" socket, and the provided 11 mm bit.
Measure the distance from the face of the adapter to the face of
the finished wall. Verify the distance is at least 7/8" (22 mm) and
no more than 1-3/8" (35 mm). Make any adjustments as needed.
Kohler Co.
Socket Wrench with Bit
7/8" (22 mm) Min -
1-3/8" (35 mm) Max
7 1080947-2-D