VERSATILE APPLICATION-- This universal y tester can test many different types of ies, and work with both standard and rechargeable household ies. Works with all 1.5v ies, AA, AAA, C, D, button cells, and 9v ies. ESSENTIAL HOME PRODUCT-- This is a must have essential household tool that allows you to keep on all ies conditions, and you will never be out of ies all a sudden. Must have item for regular and rechargeable user. NO Y NEEDED FOR OPERATION-- EASY TO USE. Clear to read, the analog display needle moves on a color-coded, calibrated scale to quickly identify "good" (green), "low" (yellow), and "replace/recharge" (red) y status. Requires no y for testing. Activated by testing y power. LIGHTWEIGHT and PORTABLE--This y tester is pocket size and very lightweight. Very easy to carry around, and does not take up storage space. Item listing--3PCS y Tester Checker Universal y Tester Monitor. If you have any questions, please contact or us. If you are not satisfied, you will receive a replacement or a full refund.