✉Dual Dial✉ Unique dual dial design, one blue and one red. Clear reading, easy to read. Pressure gauge with different color scale lines, with 4 different PSI scales, corresponding to different air conditioning refrigerants. ✉Complete Tool Set✉ Including AC manifold gauge, 3 color-coded filling hoses, 2 adjustable 1/4'' quick couplers, one 1/4'' to 1/2'' adapter, one 1/2'' to 1/4'' adapter, and a can tap. This practical AC manifold gauge set has a relatively complete set of accessories for you to use, so you don't need to buy additional extension pipes, and you don't need to worry about whether the pipe connections you buy are suitable. ✉Widely Applications✉ This A/C refrigerant diagnostic manifold gauge set is mainly suitable for refrigeration maintenance (refrigerants including CFC, HCFH, HFC, etc.), such as R12, R22, R134A, R404z, R410A and other refrigerants. ✉High Precision✉ Low Pressure Gauge(Blue Gauge): 0~500PSI/0~35BAR, High Pressure Gauge(Red Gauge): 0~800PSI/0~55BAR. The accuracy error of pointer reading is 1.5 ✉Good Quality✉ Built-in inner sealing gasket, in addition, the inner sealing gasket adopts the most popular environmentally friendly material in the world, with a long service life

How to Connect System?
1.Close the low pressure valve first, then the high pressure valve
2.The low-voltage interface is connected with the blue tube (low-voltage quick connector), and then connected with the system low-voltage and locked.
3.The high pressure interface is connected with the red tube (high pressure quick connector) and then connected with the high pressure of the system and locked.
4.The refrigerant interface is connected with the yellow pipe and the vacuum pump and locked