Each package contains one (1) unit.
Ribbed Rivet Nut Kit by Marson, includes #8-32, #10-24, #10-32, 1/4-20 Mandrel & Nosepiece, 50 Assorted Ribbed Style Rivet-Nuts, (12) M57320, M57330, M57340, (8) M57350, (6) M57354, Molded Plastic Case, and a complete set of instructions. 2.75 pound in weight (1.25kg.
It performs as advertised, but it requires a lot of force for brass and nuts. It’s been three days and my fingers are still numb from setting 145 of those in three days. However, it was extremely effective.