This optional chamber mimics the passive preinfusion you find on the venerable E61 group head. Instead of all the pump pressure flowing straight through the group head, the pre-infusion chamber diverts some of the flow resulting in a gradual 6-second ramp to full pressure. This saturates the coffee bed more gently to minimize channeling, making even extractions easier and shots more consistent!
Not sure which part you need? Parts are non-returnable so please contact us before ordering and our technicians will set you up for success.