it is one kind of carbon brushes ,also have the good works for big machines . more information about this collector : 1) Specification: 100A (copper slider) 2) Material: raw material 3) Shipment : FOB,CFR,CIF(shanghai) 4) Packing: normal packing or choose by the customers if you are interested in our products ,pls contact with us ,thank you slideway electrical appliance brush