Meade #541 Compatible 12 VDC Battery Holder for Meade ETX 90 105 125 Telescopes with Coax Power Connector 100% Meade #541 AC adapter output compatible battery holder. Use D-Cell for long lasting power Use D-Cell for long lasting power. Holds 8 D-size cells For Meade ETX-90 105 125 Telescopes with coax power connector