Leviton supplies a set of rubber grommets to compliment their metal structured wiring media center. Unfortunately, they do not supply a medium size grommet for the medium sized knock-out. This threaded hole reducer fits through the medium sized knock-out to accommodate the use of the smaller grommet.

Printed with PLA,  0.4mm nozzle, 0.2mm layer height, 3 perimeters, and 15% Grid infill.