This power cable was originally from a Motorola VM855 parent unit. Official Motorola Baby monitor power cable: model BQ05A-0501000-B (5V, 1A - so 5W of power).
Motorola Baby Monitor charger (Power cable) for parent unit / camera MBP50 VM855
MEROM 6 V 1 A Charger Compatible with Motorola Baby Monitor MBP36S Parents Unit Power Adapter Supply
Replacement Charger for Motorola Baby Monitor MBP36S – Safe & Reliable Power Supply
Motorola Baby Monitor Mbp16 Only comes with 1 wall charger
6V Charger Compatible with Motorola Baby Monitor MBP18, MBP20, MBP25, MBP33, MBP34, MBP35, MBP36, MBP41, MBP43, MBP481 Replacement Power Supply Adapter Cord
6V 1A Charger for Motorola Baby Monitor MBP18 MBP20 MBP25 MBP26 MBP33 MBP34