HIPA Carburetor Rebuild Kit RB-71 for ZAMA C1U-K54 C1U-K54A C1U-K81 C1U-K81A C1U-K81B C1U-K82 Echo SRM251 SRM251E, GT251 GT251E String Trimmer Replacement manufacturer part number: RB-71 Fitment models: ZAMA C1U-K54 C1U-K54A C1U-K81 C1U-K81A C1U-K81B C1U-K82 Echo: TC2100 SRM251 SRM251E SRM251S GT251 GT251E SV-4/E B Primer bulb included