Replacement battery fits 5 Rotronic compatible models. Specifications: 1800mAh, 3.7V, Li-ion. Compatible with: HygroPalm HP31, HygroPalm HP32, HygroPalm HP6, HygroPalm HP7, HygroPalm HP7-2. Replaces: Rotronic 1ICP10/34/50. Rotronic replacement battery designed for Equipment/Survey/Test Charger devices. Built to deliver the same performance as the original.