If your current grooming arm/holding frame is too large for the groomers helper clamp, instead of purchasing a new holding frame you can purchase this attachment that will hook on to larger grooming arms/frames. It will then allow you to use your Groomers Helper with ease. This is only needed if your grooming arm or holding frame is more than 3 cm thick.
Essentially if you have a large folding frame it is a must if you want to use your groomers helper. The down side is that it is too big for my frame and so has had to be padded to fit. It also has no grips and do needs to be tightened a lot to avoid dogs pulling it off the frame.