This 1U rackmount is specifically designed to house 2 Mac Minis, compatible with all models M1 and the older unibody ones. Upgrade design: This version of the 1U rack is an upgraded version of B09FJ6KR5G. The rack mount can handle the weight better than the previous one. Two side brackets are added for you to fix the mac mini rackmount into the 19" Rack better. And the length can be adjusted, from min 9.88 inch to max 16.8 inch. Also, the rear side of the bracket is secured with a metal side instead of zip ties.