This is a set of two Fotodiox ZJ-01 battery conversion adapters. These adapters either came with a light I purchased or were part of a set. When attached to lighting that uses V-mount batteries, I believe they allow operation with large NP-F batteries. They have been stored unused, and I have checked with a tester to ensure there are no disconnections. According to the manufacturer's website, they cost around $40. I'm selling them for less than half that price, including shipping. Shipping will be via Takkyubin Compact. Instant purchase is OK. I am also selling them individually. If you purchase all three, I will discount them to 4,500 yen, including shipping. I appreciate a smooth transaction.