if you need to work for galaxy watch ultra, please use 5V 2A adapter.

otherwise, it will not work.

Charger Adapter for Samsung Galaxy Watch 7/6/5/4 Active 2/Watch3 & Galaxy Watch FE/ Active 2 Wireless Travel Charging Dock

1. Compatible Model:
for Galaxy Watch ultra
for Galaxy Watch FE
for Galaxy Watch 7
for Galaxy Watch 4 (40mm SM-R860)
for Galaxy Watch 4 (44mm SM-R870)
for Galaxy Watch 4 classic (42mm SM-R880)
for Galaxy Watch 4 classic (46mm SM-R890)
for Galaxy Watch 3 (41mm SM-R850)
for Galaxy Watch 3 (45mm SM-R840)
for Galaxy Watch Active 1 (40mm SM-R500)
for Galaxy Watch Active 2 (40mm SM-R830)
for Galaxy Watch Active 2 (44mm SM-R820)

2. Power protection inside (ptc) keep your Samsung Galaxy Watch Active safe from over-current or over-charging.