The AT300A auxiliary power unit tester from Barfield Inc. will reduce the number of premature APU removals. It is fast to set up, easy to use, and works with various APU models. Features include resistance measurements, APU and ECU cable interface, battery noise detection, and simple go/no-go indications. The AT300A weighs only 30 pounds. For more information, call (305) 894-5408 or visit www.barfieldinc.com.