Maximize Talk Time! High Capacity 1525mAh Lithium Ion Battery and comes with blue High Capacity Battery Door for Blackberry 7510.  Be prepared to stay in touch when your original battery loses its charge. Blackberry replacement batteries provide a backup power source and also give you the opportunity to increase talk time. Be sure to match your battery with the correct sized battery door cover. FEATURES New  Original Retail Packaged 3.7V, 1525mAh Lithium Ion Battery Blackberry Original Extended Battery Blue Battery Door High performance battery Part # : 05505-018 * Compatible with RIM Blackberry 7510 (compatible with 7520 but SKU 438732, black door, needs to be purchased to match device color).