Our system holds come as a pair they are made up of:
A large jug on top, with a deep 3 finger pocket, deep 2 finger pocket and 2 angled 1st digit finger pockets. These can be used on an angled board as system holds or a cheap way to make a home training station. Screw them to a peice of plywood above a doorway to do dead hangs and pull ups.
These can be screwed onto any training wall (screws not included)