M10 x 30 x 2.5mm Black Rubber Mudguard Penny Washers - Orbital Fasteners
Nylon 66 White Black Form A Penny Fibre Rubber Washers - Universal Hardware
UBERMing 20 Pcs Black Rubber Penny Washers 30mm OD 10mm ID 2.5mm Thickness Round Spacer Gasket Flat Tap Washers Rubber for Various Plumbing Fittings : Amazon.co.uk: DIY & Tools