The U3V from Middle Atlantic is a ventilated shelf that was designed to be installed into a standard 19" rack. It creates a storage surface large enough for objects up to 17 3/8" (44.13 cm) in width. Both the base and the sides of the U3V are vented to help keep equipment cool, and 3 rear brackets are included to prevent items placed on the shelf from sliding off the back.

The U3V occupies 3 rack spaces, and has a weight capacity of 70 lbs (32 kg). It also features front and rear flanges for additional strength, and a flat black powder coat finish.