Hole plug constructed of 304 stainless steel with brushed natural finish. 22 mm hole diameter, 35 mm plug diameter. Oil resistant gasket. Secured with an 8-32x0.55 inch threaded stud and plated wing nut. Standard Pushbutton size is 30.5 mm. Designed to seal unused pushbutton holes, conduit openings and knockout holes against dust, oil and water.