Use the American Standard Extension Kit for 4 in. Center-Set Faucets and Top-Mount Faucets for your kitchen sink. This sturdy metal extension kit extends shanks 2-1/4 in. and can be used with 4 in. center-set faucets with 1/2 in. male inlet shanks and top-mount faucets with 1/2 in. male inlet shanks. Color: Brass.