Small metric hardware is a staple of building most electronics projects these days. This kit includes 10 M5 x 20mm socket sap screws with a 4mm hex socket for use with a standard 4mm Allen Key or Hex Driver. The screws are the same style as many of those found in T-slot Aluminum Extrusion hardware and feature a captive washer and spring washer to spread the load and prevent loosening of the fastener.