Review on 6-Pack No-Clean Solder Braided Wicks for Desoldering - 1.5m Length - Multi-color (1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm) by Brian Fisher

Besides being for use it makes an excellent braid to connect the brush to the brush holder, I have 2.5mm with a 9/ 32 inch compression spring uses make contact with brush and brush holder contact so the current does not have to use the spring to complete the circuit, potentially heating the spring with loss of voltage. works very well for this purpose and probably many others.