Package included: 50pcs M5 Rivet Nuts Made of hight quality aluminum, sturdy and duarable. Serration/grooves help to prevent rotation Open style, grooved-serrated-knurled Standard size chart for reference:M5: A-12mm B-0.3mmto3mm C-10mm D-1mm E-6.9mm Package: 50x Rivet Nuts Item Specifications: size: M5 Material: Aluminum