The battery is manufactured and tested under strict quality control standards before sent out. Compatible Model: K10 K420 K420N K425 K428 MS428 F670L, K10 Premier L62VL, Premier LTE L61AL Safety and Reliable: All batteries are tested before shipment, your phone will work as great as when you first got the device Build-in special microchip will prevent your battery Over-Charging, Over-Discharging, Over-Heating and Short-Circuiting Customer Service: Please contact us if there is any problem with our product, we promise you a satisfaction resolution in 24 hours. 1