A MUST HAVE PRESSURE GAUGE: Special design for coffee machine with E-61 grouphead, help you monitor the extraction of the coffee easily. INTALLES IN MINUTES: Come with install tool and user manual, no worry about the tools and intallation knowledge. (Kindly note: Before installation,make sure the E61 machine is turned off and cooled down.) USER-FRIENDLY GAUGE DESIGN: This E61 gauge scale from 0-16 Bar, as the optimal pressure value is 9 bar, we highlighted the 8-10 scale range for better control of extraction, no more hesitation when make your delicious shot. PACEKGE: 1* e61 group head Pump Gauge, 2* washers (Need to be used togather), User manual, 1* Wrench.