Spot Supplies 9.5mm 10mm 10.0mm 9.5 10 10.5 Mm Hole Transparent Black Soft Rubber Plug For Water Proof Door Cover Gasket Stopper - Gaskets - AliExpress
T Type Round Silicone Rubber Stopper end cap rubber tube plug with 3.75mm hole for 10mm 10 mm hole 10.6mm 25/64" 13/32" Diameter - AliExpress Computer & Office
10mm~29mm Silicone Rubber Plug Blanking End Cap Tube Pipe Insert Bung With Holes | eBay