This little stainless steel screw may be the ultimate illustration of La Marzocco's attention to detail. Sure, it functions to keep the shower screen in place, but it's also been carefully designed to do a lot more than that. Thanks to its precisely placed holes, it actually helps to ensure that water disperses evenly, both while pulling a shot, and while steam flushing the group head. Buy one of these screws if you lose or damage the one that came with you La Marzocco machine. It fits any domestic or commercial model, and is made of stainless steel for durability. Please note that this is the newer design of the La Marzocco diffuser screw (part code A5110) and can be retrofitted to all older machines.