Have a full set (4) of adapters. They are 25mm thick and allow a vehicle with a 5x112 bolt pattern to run wheels that have a 5x120 bolt pattern (BMW, Land Rover, Jaguar, etc.). They are in excellent condition and come with 16 lugs, so you can use your own lock lugs and key. The adapters are 57.1mm hub-centric.
I don't know who they are manufactured by, but they are lightweight and probably made out of aluminum. They do have some markings on the back which are pictured.