Product Description GJ Works 220pc One Way Security Screw Assortment GKA220 This handy workshop kit contains a total of 220 one-way security screws in 10 different sizes, making it an ideal kit to keep in the workshop or service truck one-way screw design allows you to fasten items such as number plates, compliance plates and other items and reduce theft and/or tampering as the head only allows for the fastener to be tightened and not loosened Features Zinc Plated 10 Sizes: 3.5mm to 6mm Dia. Lengths: 19mm to 25mm 220 Piece