Savior Single D Style Carb Carburetor Adjustment Tool 308535001 Screwdriver for 2 Cycle Craftsman Ryobi Homelite String Trimmer Chainsaw Carburetor Adjusting Tool High quality replacement adjustment tool for Single D style screw Refer to Part No.: 308535001 These tools are a "must" to keep these 50 hr rated, small, 2 cycle, machines running.