This is a porta-filter for an espresso coffee machine. Coffee grounds are placed inside the removable filter, which is placed inside the cup portion of the porta-filter (filter sold separately). The porta-filter is then positioned underneath the brew head, and attached by moving the retainer clip back, lining up the handle with the open l...Read moreock icon and fitting it into the groove. Then turn it slowly to the right until the retention clip is aligned with the closed lock symbol. The porta-filter is not dishwasher-friendly. It should be washed after each use with warm soapy water and rinsed thoroughly. This is an OEM part, designed by the manufacturer to perfectly replace the original.