Professional 16”Rivet Nut Setter Kit features longer carbon steel arm maximizing leverage for saving user energy. Come with 12PCS interchangeable mandrels and 120pcs rivet nuts. Use Guide: 1.Choose the right mandrel sets for rivet size, install it onto the tool head. 2. Insert the gun top into the hole for riveting. 3. Close the handle, rivet the nut to the right position until the nut is secure. 4. Withdrawn rivet tool by rotating the knob in a counterclockwise direction, complete the riveting. Package Includes: 1 × 16 inch Rivet Nut tool 12× Mandrels 120× Rivets Nuts 1 × Multifunctional Spanner 1 × User Manual Please note that the M8 mandrel was installed in the tool