The RL2676TW is a 2.25" x 1.25" weatherproof thermal transfer roll label on a 1" core with a 4" outer diameter. This is a white material. At this time we don't offer any metallic materials on rolls. For the Cab MACH4, this is not a printer we've tested with so you'll want to review the printer model's specifications to see if our product meets its requirements.