Cyborg Hand

My grandson received a Mega Cyborg Hand kit for his tenth birthday. It was more than he could handle, so my husband took over the project. He was almost done building it when he discovered that there were some missing pieces. I contacted the company and they sent the parts right away. They arrived yesterday, and the hand was completed today. It has hydraulic fingers and I have no clue how it works. Hopefully, my grandson will be able to figure it out.