Pipe cap for aluminum, stainless steel and iron with a diameter of 1.0 to 1.6 mm and thickness of 0.04 to 0.06 inches (25 mm). It is a little larger than 1.0 inch (25 mm), so it can be used for pipes with a diameter of 1.0 inch (25.Use a wood hammer or something to push into the pipe and cover the lid. Set of 4 Free Shipping for Any Set