This kit contains everything needed to convert your V2 SMP over to a V3 SMP, or a V3 SMP to a V2 SMP. For each conversion kit, it will include a trigger board and either a standard V2(M4) or V3(AK) nozzle. The V3 to V2 conversion also includes a buffer tube adapter.
Additionally, you may be interested in a different length wire harness. More harness lengths are available here.