The bottomless portafilter includes a standard triple insert basket.
The single spouted portafilter includes a single insert basket.
The double spouted portafilter includes a double insert basket.
What is a bottomless portafilter and what is it used for? Bottomless portafilters are used as a training tool. It will provide you with immediate feedback and can see if channeling occurs right away. Channeling is the rapid passage of water through fractures in the coffee puck, which produces a thinner, under-extracted espresso. When it occurs, you'll often see sudden appearances of blond streaks in the stream of espresso; sometimes the puck will even have pencil lead-sized holes where channeling occurred.
The La Cimbali Bottomless Portafilter fits almost all of the Cimbali machines, including the Junior Casa.
NOTE: This does not fit the lever-action piston Cimbali.
NOTE: As of 6/26/19 we started purchasing these through a different vendor, so they're going to look slightly different than what is pictured here. They will NOT have the same handle as the Cimbali branded portafilters.