To start with the driver grips the main pin closest to the wheel which leaves his wrist enclosed within the two smaller pins.
Firstly this provides wrist support when you’re not engaging the wheel which is comfortable for most, but a necessity for others who have weak wrists such as is caused by arthritis. If you’re one of these people it may be worth looking into palm grip aid which is specifically designed for people with poor grips and weak hands.
Aside from making non-engagement easier, the two pins also provide support and leverage for turning the wheel when required.
All the pins are padded for extra comfort, and the placement of the device is usually lower down and parallel with the hand control so that you’re not exerting too much effort in keep your arm high.
The counter balance was specifically designed to be used in conjunction with tri-pin grip which can be quite heavy and so can have its mass (weight) offset which means the driver doesn’t have to compensate – which is again useful for those with problems exceeding paraplegia or partial leg use.
It’s worth pointing out that mps monarch has a similar steering aid which is very similar and equally obtainable (as opposed to GuidoSimplex for example) incase your local disabled car dealership doesn’t stock this specific Mobility Products and Design model (the model number is 3522).
The pins are fully adjustable which means you can position them to fit your hand specifically, and its mountable anywhere on the steering wheel if required.
Finally the foam protection cover is replaceable when it gets too old or worn down.
I’ve mentioned this before but I do think that this is probably the best steering wheel control available although there are several competitors such as the V-grip which allows the hand and wrist to be enclosed in aluminum wrap while retaining a single pin to engage and turn the wheel.