The black plastic bracket encloses the otherwise exposed gears, and the mounting tabs capture the nuts for easy installation. The brackets are sold in pairs, and each bracket comes with four #2-56×7/16" screws and four nuts.
These plastic mounting brackets allow you to easily and securely mount the ubiquitous 10 mm × 12 mm × 26 mm metal gearhead motors first popularized by Sanyo’s 12GN series (e.g. NA1S…NA3S).
These brackets have mounting holes that are very close to the output shaft end of the motor, which could cause mounting difficulties if your wheels have recessed hubs like the Pololu Wheel 42×19 mm. For such applications, we recommend the extended version of this bracket.