These spacers have advantages over metal spacers. All the spacers made of ABS plastic, lightweight, non-conductive, non-rusting, and corrosion-resistant. It is used to keep boards at a consistent height and prevent the joint from bending, twisting, and short-circuiting with a middle partition design. Fit for 3D Printer, TV Wall Mounting, Electrical Outlet, Pegboard, Robot, Fpv, Quadcopter, Computer.