Pb fastener self adhesive pcb spacers 4mm pcb hole pb fastener lcbsb 4a this self adhesive pcb spacer from pb fastener amp components is a dome shaped spacer designed for a 4mm pcb hole and equipped with a 64mm spacer body with self adhesive square panel manufactured using a durable lightweight plastic which provides a strong dependable grip and remains compatible with a 16mm thick printed circuit board pb fastener lcbsb 4a rt self adhesive pcb spacer