This is a set of two Fotodiox ZJ-01 battery conversion adapters. These adapters came with a light I purchased. When attached to lighting that uses V-mount batteries, they should allow operation with large NP-F batteries. They have been stored unused, and I have checked them with a tester to ensure there are no disconnections. According to the US website, they cost about $40 each. Instant purchase is OK. No price reduction. Please ensure a smooth transaction.