Low Pressure AC hose?

I'm hoping someone can steer me to the correct fitting. I want to recharge my AC and I'm looking for the low pressure fitting on my 05 impala. On the firewall behind the engine I see a fitting to hook up to, it's on the larger piping going into my evaporator (?). Is this the low pressure? It seems to be the only hook up.

I'm hoping someone can steer me to the correct fitting. I want to recharge my AC and I'm looking for the low pressure fitting on my 05 impala. On the firewall behind the engine I see a fitting to hook up to, it's on the larger piping going into my evaporator (?). Is this the low pressure? It seems to be the only hook up.

with r134 the recharge adaptor is the larger fitting...yes this goes to the evaporator...just remember it is best to put too little in then too much...once you get the pressure to 40-45psi with the fan on high and the windows open at 80deg f air temp stop charging... if you put too much in vent out slowly until the correct pressures are at this fitting...if the leaking is at the compressor seal [oil leak] you may need to add a oil charge of a few oz... napa sells the correct pag oil for GM....I think PAG 150...