What We Like About This Mobile Roll File The most unique feature seen here is the slanted top grid, creating appropriate compartments for shorter files and preventing them from getting lost amid longer files. Combined with the black powder-coat finish and thick side bars, this is a great roll file for the home or office. Heavy-duty wire frame with black, power-coated finish * Double-reinforced wire frame with lip on bottom grid * 3/8-inch diameter side bars and two-level grid organizers * Houses 20 roll files up to 4 inches in diameter * Four, dual-wheeled, locking casters