Quick Mill Walnut Handle Bottomless PortafilterQuick Mill Bottomless Portafilter Overview The Quick Mill Bottomless Portafilter is a 58mm portafilter with a walnut handle that can fit with all Quick Mill espresso machines, so you can take advantage of the benefits of a bottomless portafilter. Whether youre interested in additional clearance so you can brew into taller cups and mugs, a clear view of how your espresso shot is pulling so you can diagnose issues like channeling, or the ability to brew