https://www.mccoys.com/shop/p/12492074/1-in-brass-snap-plug
The Hillman 838670 1 in. Brass Snap Plug forms a tight seal around the mouth of a drain and locks, or snaps, into place when the handle is closed. To install, place the brass plug into a 1-inch diameter drain opening and turn handle clockwise. To remove, lift the handle and turn the drain plug counter-clockwise. The brass handle resists rust while the high-strength rubber plug offers consistent, secure function even after long periods of repeated use. These brass snap plugs for drains are part of Hillman's Deep Drawer specialty program.