Attention The blue one is low pressure the red one is high pressure Please check it before placing an order Thank you Description R134aAC Quick Connector Adapter Coupler with Low High HVACSpecifications ModelR134aMaterialBrassmetaColor Blue RedSize47x30mmSuitable Forair conditioning refrigeration systems fluorideFeatures 1 R134A Quick connect refrigerant air conditioning Adapter 2 Red for high pressure and blue for low pressure 3 The quick connect design has an integral safety 4 Sleeve which protects against injury and refrigerant loss5 if the coupler is disconnected under pressure Package included 1 x Adapter