Purchased from Yodobashi Camera. It's very convenient because you can carry the lens around your neck for shooting! GoWing is apparently a Korean brand. This is a GoWing lens holder. Compatible with Canon RF lenses. I don't use it much because I don't have many interchangeable lenses. It comes with the box and instruction manual. I'd be happy to sell it to someone who doesn't mind it being used. Note: It's for RF mount, so it only works with RF lenses and not EF lenses.