Silent Puck Ejector Tool:With this suction ball ,you could blow out the coffee puck quietly and needn't tap your portafilter loudly.This device saves wear and tear of your portafilter, eliminating the need to "knock out" your pucks. Premium Construction: It is made of silicone rubber which is a high-adsorption materials to withstand repeated use and ensure long-lasting performance. This tool has high mechanical strength to pushout the coffee residues. How to use:Put some light pressure into the portafilter to create the seal and squeeze it evenly without accidentally pulling the edges off the portafilter.not suck coffee back into the device. (Lift away from portafilter before unsqueezing) Quiet Coffee Extraction:Works like a charm to push coffee quietly out of bottomless portafilters, making it perfect for early risers who don't want to disturb their family.In the morning just to get the puck out .great for specialty coffee fanatic or just an espresso Lover. Compatibility with:The bottom of suction ball is 58mm,it only compatible with espresso bottomless 58 portafilter.but not fit for partially open naked portafilter(bottomed portafilter. Colour:Black Material:Silicone Package Contents: 1 * suction ball Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.