Basic type rail-attach bracket will attach to standard accessory rails. This model of grip folds 90 degrees to sit against the weapon flat or hold out as a vertical grip.
The front of the grip has a hand-stop to help prevent enthusiastic movement wandering that hand in front of the muzzle. The ergonomic shape and texture might not be the most comfortable in the world but the grip is great, particularly for digging down on gloves.
The grip also has a pull out extension that doubles the stubby grip into a full sized grip. Pressing the release catches on both sides causes the extension to spring back up.