Teenage Engineering ZM-2 Rumble Expansion Module with Silent Metronome for OP-Z Portable Synthesizer

I'm giving this five stars because I got it when it was heavily discounted - if only I'd seen a line module at the same sort of price cut! The rumble back does enhance the OP-Z experience slightly, but functionally it really doesn't alter it as an instrument. For completists, it makes the Teenage Engineering "quirky" vision of an instrument that is almost like a game controller complete. But if you're buying upgrades for your OP-Z, the Oplab should occupy the slot if you play with a lot of synths or modular, the Line module should be your choice of expansion if you play with samples and sounds. Rumble is amusing, but it almost feels like it should be in the OP-Z instead of the placeholder plastic :/

Hugely overpriced and totally unnecessary - but you’ll miss it once you stop using it!!!