The Haltec Rubber Rim Hole Plug is a rubber plug designed to seal holes in wheel rims. It has a tapered design to fit different hole sizes and is made of durable rubber that resists cracking, weathering, and aging. The plugs come in a pack of 100 and fit hole sizes ranging from 5/16 inch to 3/4 inch. They can seal spoke holes, valve stem holes, and other rim holes to prevent air leaks. The plugs are easy to install by simply tapping into the hole with a hammer. Overall, the Haltec Rubber Rim Hole Plugs provide an effective and affordable way to seal holes in wheel rims.