THE BOSS™ Foam Cannon metering tips are matched to the type of pressure washer you have so the foam will fly non-stop. Pink tips are for gas-powered pressure washers (2,200 psi & up) Purple tips are for electric pressure washers (1,100 to 2,200 psi) Aqua tips generate maximum foam in all pressure washers Pink tips can be used in the Foaming Sprayer Replacement for lost or worn tips The orifice of these tips and the viscosity of innovative BOSS™ foaming liquids are calibrated to provide the perfect mixing ratio when using the Auto-Mix metering system. The Auto-Mix system takes the guesswork out of snow foam... No mixing, no mess, no math, just screw a bottle of foaming concentrate onto the cannon and get ready for a blizzard of foam. The pink tips can also be installed in the Griot\'s Garage Foaming Sprayer when the sprayer is used to dispense any BOSS™ Foaming System liquid.