If you haven't yet seen the coloration, or 'Tiger Stripes', that appear when good espresso is pulled through a bottomless portafilter–you're really missing out. The Rocket Espresso 58mm Bottomless Portafilter offers a clear view into the extraction process as rich hues of brown and caramel coffees are pulled through your portafilter only to waterfall into your shot glass like a thick molasses. Now just imagine what that tastes like! Earn your stripes and make espresso you know you'll love with the Rocket Espresso 58mm Bottomless Portafilter.How the 58mm Bottomless Portafilter Works Lightly fill the portafilter basket to the top Use your finger to gently even out the grounds Lightly press the tamper into the grounds and find a good center point Evenly apply approximately 30 lbs of pressure to the grounds Tap the side of the portafilter to reveal loose grounds Lightly tamp these loose grounds into place Sit back and enjoy one of the coolest looking effects in espresso extraction