The Sony HVL-20DW2 Video light is switchable between 10W and
20W. Designed to mount onto the camcorder's accessory shoe, the HVL-20DW2
provides 10W operation when used with an NPF-550 InfoLithium battery, and 20W
operation when used with NP-F750 or NP-F960 InfoLithium batteries (batteries
must be purchased separately).