This nut riveting tool kit from Laser Tools comprises of a nut riveting tool with 4 different head sizes: M3, M4, M5 and M6. The comfortable handle with ergonomic grip provides ease of use. The kit also includes 40 assorted nut rivets in various sizes. It is an ideal starter kit for nut riveting and is capable of riveting M3, M4, M5 and M6 sizes. Additional packs of nut rivets are available to purchase separately.