This spring is an experimental piece used to modify the behaviour of the espresso shot. Generally, it slows down the flow, leading to longer shot times when all other variables are the same. The mechanism it achieves that is possibly by: reducing expansion of the puck during the shot, compresses the puck further during the shot while the puck degrades, or just simply prevents the puck screen or mesh screen from lifting due to water flow. This is meant to fit inside a basket with a minimum diameter of 49mm, and fits between the shower screen of your espresso machine and the puck screen or mesh screen on top of your puck. It's made of 304 stainless steel. Requirements Espresso machine with a shower screen Puck screen or mesh screen above the espresso puck (spring should not directly sit on tamped coffee)
