Replacement battery fits 6 BW compatible models. Specifications: 1200mAh, 3.7V, Li-Polymer. Compatible with: Gasalert Microclip Gas Detector, GasAlert Micro Clip XL, MCXL-MPCB1, MC-XW00, MC-XW00-Y, MC-XW00-Y-CN-00. Replaces: BW AEC603658. BW replacement battery designed for Equipment/Survey/Test Charger devices. Built to deliver the same performance as the original.