The Miniature Haptuator Amplifier is a Class G haptic amplifier board meant for amplification of signals to fed into the Planar Haptuator while using as little a space as possible. It measures 12mmx12mm.
If you drive continuous haptic feedback into the Haptuator, consider mounting this amplifier on a thermally conductive surface with non-conductive adhesive that can draw heat away. It can become quite hot.
You can drive the amplifier with a USB source, but it has to be able to provide close to 1000mA.