Rancilio MD-40 Grind Adjustment Collar Brand_Voss though draining the water lines

though draining the water lines first is recommended

protecting the boiler from over-pressurization on Millennium

If your old knob spins freely without opening the valve

then only a partial turn with a wrench - overtightening compression nuts on supply lines is a common cause of a cracked ferrule and a slow leak months later

don't mix this with a non-Parker coil

Rancilio MD-40 Grind Adjustment Collar Brand_Voss though draining the water linesRancilio MD 40 Grind Adjustment Collar This collar adjusts grind size on the Rancilio MD 40 grinder. This is a special order item shipped directly from the manufacturer separately from the rest of your order: in stock units ship fast, while out of stock units typically require 1 2 weeks for processing before shipping. SPECIFICATIONS: Dimensions: 117. 5mm OD x 57mm ID COMPATIBILITY: Fits: Rancilio MD 40 grinder Replaces: OEM MD 40 grind adjustment