CISA - Flag Brass Bell Button 100mm for Lock Mounting 50-50mm Gold - 8010-23

CISA - Flag Brass Bell Button 100mm for Lock Mounting 50-50mm  Gold - 8010-23

Cisa security lock cylinder, in gold color, with dimensions 50-50mm. 
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 100mm, with the piece from the screw socket to the outer part of the door being 50mm and the part from the socket to the inner part of the door being 50mm.