High Temp Silicon Plugs stop powder coating, ceramic coating, paint, and more from getting into places you dont want them. You will receive 25 - 1/4"x3/8" plugs. These plugs at their smallest diameter measure .246" and .357" at their widest and measure 1" long. Plugs can withstand temperatures up to 600°F. This silicone rubber is flexible to fit rough surfaces and works in both threaded and non-threaded holes. These are tapered to allow the plugs to fit many hole sizes.