I/O CREST SY-ACC65063 Mobile Desktop Tower Computer Metal Floor Stand Rolling Caster Wheels with Tall Support Walls and Adjustable Width from 6" to 10" Adjustable width: 5.5" - 9.75" 5.5" tall side walls 4 Wheels, 2 with stopper Adjustable Width: 5.5" - 9.75" 5.5" Tall Side Walls Two Front Locking caster wheels