This reservoir holds a small volume of hot water static until a shot is pulled, and then the water is released prior to pressurized water being introduced, briefly wetting the coffee puck. Can be used (but is not always found) on any solenoid operated San Marco group head. 1/4" Male BSP thread.
WARNING: This product can expose you to chemicals including lead, which are known to the State of California to cause cancer, birth defects, or other reproductive harm. For more information, go to www.p65warnings.ca.gov.