Features and Benefits:Fully automatic operation — program for service, walk away and return when complete98.5% recovery efficiencyCharge accuracy within +/- ½ oz.Automatic internal tank refill. No stopping to fill the internal tank during service, or before service.Automatic oil drain shows how much oil was removed from the system during service.Integrated refrigerant identifierProgrammable vacuum operation helps get to the necessary vacuum level in any condition quicklySystem leak test to identify gross leaks in a systemExceeds SAE J2843 requirement for R-1234YF Recover, Recycle and Recharge equipmentUses 34724 filter or 13172 maintenance kitThe mechanical scale lock eliminates the need to recalibrate your refrigerant scale after transporting the machine long distances, saving time. The AC1234-4SL is a fully automatic R-1234yf ACS machine with an integrated scale lock, designed for mobile service. The mechanical scale lock eliminates the need to recalibrate your refrigerant scale after transporting the machine long distances, saving time. Accessible from outside the machine, the lock secures the scale, preventing damage or inaccurate refrigerant measurement. The internal tank stays on the scale during transport. A safe startup feature prevents the machine from powering on if the lock is engaged. Extra-long 12' hoses make mobile service easier. An indicator light reminds technicians to lock the scale before transport, while special tie-down points and guidelines ensure your machine is safe and secure for mobile service.