How does this thing work again?

Left work and came home to sort a few things out. One of the members of the dive club is looking to get a twin set. She has been trying out a few people’s sets in the pool. Last week I offered our setup for her to try.
Came home and had to piece it together. We hadn't dived since Mexico so the kit needed to be reconfigured. Good job really as the cylinders are out of test at the end of August and the high pressure hose I fitted was damaged.
Still managed to get it working. Seems that our setup was the best one she had tried so far and was along the lines she had already been thinking about.
Managed to do 1/2 a mile in the pool as well. Still can't breath on both sides properly. Think I might need a few lessons in the near future.