Vertiflex Smartworx Companion File, 22 1/2w x 12 3/8d x 14 1/2h, Matte GrayFor letter size hanging file folders. Sized to roll under Vertiflex Smartworx File Carts (sold separately) or any standard height work surface. Durable steel and wire construction. Four twin-wheel casters, two locking. Color: Matte Gray; Caster/Glide/Wheel: Four Twin-Wheel Casters (2 Locking); Material(s): Steel; Wire; Overall Width: 22 1/2".