Professional Nut Riveter for Captive Nuts with 4 Fittings You use this blind riverter exactly the same as you would use a pop riveter. Blind Rivet Nuts are internally threaded rivets that can be installed into sheet-metal, tubing, extrusions, and plastics.Blind Rivet Nuts provide a reliable system of inserting high quality load bearing threads.It comes complete with 3mm, 4mm, 5mm & 6mm adaptors.The handle position holder doubles up as a spanner to tighten the inset into the riveter head (see pictures)Please note the heads for the rivet gun are a left hand threadSpecification 3mm adaptor 4mm adaptor 5mm adaptor 6mm adaptor Cushioned handles Position holder/spanner