Durable 8" rubber tires for laptop security carts allow for limited outdoor use on 16, 24 and 30 module notebook PC security carts. Kit includes: Four 8"H x 2"W swiveling tires on nylon roller-bearing hubs with thread guards, 135 X 110 mm plate mount and two Max-Lok top-mounted brakes 8" Tire Kit - air hollowed rubber tires (set of 4) for limited outdoor use (pre-installed when ordered w/ cart) Durable rubber tires for laptop security carts Limited Outdoor use for 16, 24 and 30 module carts Can be used on models DS-NSC-16, DS-NSC-24 and DS-NSC-30 Four 8"H x 2"W swiveling tires on nylon roller-bearing hubs Two locking tires with Max-Lok top-mounted brakes 135 X 110 mm plate mount DS-OTK