CISA - Flag Brass Bell Button 80mm for Lock Mounting 45-45mm Gold - 154907

CISA - Flag Brass Bell Button 80mm for Lock Mounting 40-40mm Gold - 154907

Cisa security lock cylinder, in gold color, with dimensions 40-40mm. 
The total length of the cylinder of a lock consists of two dimensions. 
The first starts from one end to the center of the belly button, where the screw is placed, while the second concerns the distance from the center to the other end of the belly button. 
Usually the hole for the screw is not located exactly in the middle of the cylinder and the part with the smallest dimension is placed on the outer side of the door. 
In this case the total length of the cylinder is 80mm, with the piece from the screw socket to the outer part of the door being 40mm and the part from the socket to the inner part of the door being 40mm.