A 58mm espresso distribution tool, sometimes called a leveler, evens out the coffee in your portafilter basket before you tamp. You set it on the basket, give it a few turns, and it spreads the grounds into a flat, even bed. That matters because uneven coffee lets water find the easy path through the puck, which is called channeling, and channeling gives you a shot that is sour and bitter at the same time. First, check your size This one is 58mm, the standard size for most prosumer and commercial-style machines. It will not fit 51mm or 54mm baskets. If you are not sure what you have, measure the inside diameter of your portafilter basket across the top. I carry distribution tools for the other common sizes too. Who this is for Home baristas whose shots taste different every morning even though they think they are doing the same thing. A leveler takes one variable out of the equation, which makes dialing in your grinder a lot less frustrating. It is not magic, and it will not fix stale beans or a bad grind, but it makes good coffee repeatable. The details Size: 58mm Depth: adjustable, so you can match it to your dose and basket Build: all-metal construction Finish: black, with the Espresso Parts Jolly Roger logo Maker: Espresso Parts, from their Barista Basics line of professional bar tools How to set the depth Loosen the top. Hold the middle section and turn the top counterclockwise one or two full turns. Do not take it off. Adjust the fins. Turn the bottom silver section clockwise to push the fins deeper into the basket, or counterclockwise for a shallower setting. Lock it. Turn the top clockwise to tighten once the height is right. Use it. Rest it on the basket, spin a few times, then tamp. A good starting point: set it so the fins just touch the coffee and leave a light pattern, not so deep that they are compressing it. If it is packing the coffee down, back it off. Honest notes A distribution tool is a finishing step, not a replacement for a tamper; you still need to tamp after. Some people pair it with a needle-style WDT tool for clumpy grinders. Start with this one alone and see how your shots change. Backed by my 30-day satisfaction guarantee, and I answer my own email if you want help picking the right size.