Cameron sino 1100mAh Li-ion Battery 37-00030-001, E4MT181202B12, MX0708 Replacement for Magellan Maestro 4000 4010 4000T 4040 4050 GPS Navigator with Tools Kit 12 Months Warranty Replacement for the Following Battery Model/Part Numbers:37-00030-001, E4MT181202B12, MX0708 Compatible with the Following Models:Magellan Maestro 4000, Maestro 4010, Maestro 4000T, Maestro 4040, Maestro 4050. Capacity: 1100mAh 3.7V Li-ion Rechargeable Battery Pack With Installation Tools Kit. Cameron Sino Over 10 Years Battery Manufacturing Experience