Dual Charger for Polycom / SpectraLink 8400 Series Battery Packs. Includes USB Type C power supply. Charges both Phone and Spare battery. Both Standard and Extended Batteries in 5 hours or less! Features durable Gold Pins to ensure a more consistent and long-term connection with the battery pack for each charge, and LED lights to indicate each batterys charging status. Compatible Battery Models: 1520-37214-001, RS657, 1520-37215-001, RS658