The Carburetor Diaphragm 391681 is a reliable aftermarket part designed to fit Briggs and Stratton 3.5 & 4 HP vertical models. This engine part is specifically compatible with for aftermarket equipment and comes in a package quantity of 1. It includes a carburetor diaphragm kit, providing the necessary components for a complete replacement. Made to the highest standards of quality, this part ensures optimal performance and durability for your lawn mower engine.