about this project620 pcs male and female JST SM connector combo kit for DIY projects, easy to use, just put the crimpers in the tool and press them so that the insulation of the crimpers is all the way towards the wires.High-quality, crimp-pin connectors are made of durable plastic and tin-plated metal with pure copper inside for increased conductivity and surface coated with anti-oxidants for extended lifeJST SM 1 / 2 / 3 / 4 / 5 / 6 pin terminal, 18-26 AWG wire, pitch: 2.54mm, these jumper pin connectors are compatible with arduino and breadboard style pin connectors and sockets, such as 3d printing boards waitPackage includes 200 female crimp contacts; 200 male crimp contacts; 10 pcs 2x6p, 10 pcs 2x5p, 10 pcs 2x4p, 10 pcs 2x3p, 10 pcs 2x2p, 20 pcs 1x6p, 20 pcs 1x5p, 20 pcs 1x4p, 20 pcs 1x3p, 40 pcs 1x2p, 5 0 pcs 1x1p Dupont cable jumper headersAll products are packed in a clear plastic storage box with 11 divided units, each unit is sized to fit the pin housing connectors, male and female Dupont crimp pins are always kept compact and organized",