This rigid enclosure holds tightly onto your N20 motor providing you with 4mm diameter thru-holes for mounting from the top, bottom, front, or back. Besides making it easier to mount, your N20, this enclosure provides some level of protection to the exposed gears of the N20s gearbox.
There are three access holes through which motor wires can exit the enclosure (one on the back and two on the sides) allowing you to keep your wiring clean. There is room inside to enable the enclosure to be used with N20s which have an encoder on the back. There is also room to have a Gear Motor Input Board soldered on the back of an N20 (without encoder) with a JST RCY plugged in.