Plastic M3x12mm Electric Isolating Single Head Hexagonal Threaded Spacers Spacers are unthreaded tubes that separate, space, or connect components within a system to ensure proper placement. Round spacers (also called clearance spacers) are the standard shape, while hex and square styles have flat sides that can be gripped with a wrench or pliers. Product Name: single head hexagonal Spacers; Material: nylon; female/male thread:3mm; size:M3*12mm(inner D*H) Color: as picture show;