These insulating screw washers for use on motherboards, PCB's and circuit boards. The screw washers are made of fiber material. Black fiber washers for your machine builders out there. Product dimensions: 0.4" Width x 0.4" Depth x 0.04" Height Product weight: 0.04 lb Round Shape Fiber Material Size: 12" Color: Black Usage Tips: - Additional info: - GR-FBW-12-BLACK #01348