! The Delkin Battery Tester can test AA, AAA, CRV3, 9V, and 2CR5 batteries accurately for remaining battery life. The only power required to run the tester is supplied by the battery inserted into the tester slot no adapters required. A switch allows the user to test either primary or rechargeable batteries, and LED lights quickly indicate how much power is remaining once a battery is inserted. The tester is designed to be small, lightweight, and portable so that it fits easily into your camera bag. Two year limited warranty.