Magnetic hold-down for laser cutters

This is a hold-down meant to enclose and protect a standard 30x3mm circular rare earth magnet, and can be used to hold down small/thin/lightweight/flexible materials inside of a laser cutter like the Glowforge that has a fan strong enough to blow them around. The edges have overhangs meant to hold 3mm and 6mm material pinched from the side (it usually takes at least 4 to hold something firmly). They are designed to be short enough to fit under the 1/2" clearance of the Glowforge's carriage.