Simply select the Thread Form, type of Screw and length from the main category selection add them to yourcart then add the relevant venting from this category, i.e. you want M3 x 12 metric Socket Allen Capscrew, go to Metric>Socket Allen>Socket Capscrews scroll to M3 x12 add to basket then go into Vented Hollow Category>Metric>M3 then add, to your cart the coresponding qty. Min qty 50 per fastener. Vented Hollow Stainless Screws in Metric, Unified, BA, BSf & BSw thread forms. Socket Allen, Hexagon & Machine Screw forms