Since 1965 Lenmar has been building award winning, high quality power related products. Lenmar personally manages the excellence of our products through every aspect from design to production. Fits: Plantronics Savi WH500,W440,W740, W745 Replaces: Plantronics 84598-01 Specifications: Voltage: 3.7V Capacity: 140mAh Chemistry: Lithium Polymer Warranty: 1 Year.