It allows to join together the bottom chassis and snap into top board, without screws, within the specified panel range, in a quick and easy way. Our spacer eliminates screws, nuts, and lock washers in mounting P.C. boards on metal chassis or stacking in multiple tiers. A unique locking clip provides a mechanically secure, reusable connection in pre-drilled or punched holes while saving considerable assembly time. This product is perfect for panels with a top hole diameter of 4,0 mm.