Carling Type 6 Rocker Clip Panel Holder ARB Switches Housing Plastic the drill size for mounting 1 pc : 52mm x 27mm.Quantity: 6pcs side rocker switch pannel Material:?Plastic.basically Carling Contura switch Inner dimension:22mmx38mmx27mm/pcs Interlocking,designed to give more strength when mounting switches in your dash. This strong bracket gives you unlimited options to mount many extra switches to your vehicle or boat Limited 3 Year Warranty