This plastic intake manifold fits 23-39cc 2-Stroke engines requiring a carburetor with a 10-12mm Venturi Opening. This part mounts with 2 bolts to engine side and carburetor then mounts with 2 bolts to intake. Bolts not included. Measures: 1.5" (H) x 2" (W). Note the position of the vacuum hole to ensure proper fit.