This is a replacement ProTek R/C Samurai RM, 321B 21j Carburetor. This carburetor is fully assembled with an installed 7mm Elliptical carb restrictor, and includes one carb neck o-ring and insulator washer. 

This three needle slide valve carburetor features a black carburetor body finish with a black aluminum carburetor insert and an easy to access idle screw.