HYDRA GEN 2Includes HYDRA HPA Engine Integrated Filtered Line Premium FCU Universal Wiring Kit 14 Wiring Harness O Ring Kit 2 x 3 Patch The HYDRA Gen 2 utilizes our proprietary hybrid open closed bolt technology from the INFERNO Gen 2. It functions and performs like our INFERNO Gen 2, but with offset nozzles. The HYDRA was the first out of the box drop in HPA engine for guns with offset nozzles. Convert guns like the M14, P90, Tavor, and more into an HPA monster