One-touch hook Wave plate hook L-shaped angle Silver For attaching wave plates. Purchased from a home center. I've disposed of the box, so I don't know the exact size, but I think it's 19mm. 2mm pitch is difficult, and I'm not even sure if I'm measuring correctly with my calipers... I can't say for sure. Stainless steel diameter: Approximately 19-20mm Sponge diameter: Approximately 18mm+, black Stored at home. Unused items were stored in a Tupperware container. Not made of PVC, so it's durable and long-lasting. Currently have 70 pieces available. Shipping method may change between Yu-Yu and Raku-Raku. #minitoolroom Wave plate, exterior wall, roof DIY, carpenter, maintenance