Well, that it works by foot pump could indicate that an unpowered device is possible (or in fact being used), depending on the build. The foot pump to me is the only clever bit! Simply put, the only wrist action it replaces is the inverted portafilter occasional second knock, but a knock box allows for a wider range of potential working positions and the slope is straight. having this pull the puck out cleanly from above would be the clever thing, as it doesn't get rid of any RSI when you're turning the damp portafilter upside down and trying to accurately and repeatably get a seal using metal on metal. And damaging the shower screen seal? They're replaceable items designed to wear out. If you're in an environment where the staff are using a knock box with a bump bar that damaged to smash up your baskets without comment (and aiming for the bit where the rubber isn't, you've got bigger problems than the lack of a suck box. *Still, it happens to be a coffee toy. I want one of these. I'd prefer a checkerboard knockbox, portafilter handle + galatea wheels. CH
