This would be for an older light. Specs are JC12V50W 20H/G2. 2 prong design. Just a note, don't touch the bulb with your fingers. This will cause your body oils to be on the bulb and potentially it could not work then. Use a piece of toilet paper or kleenex to handle the bulb.
These are for an older Halcyon 50 Watt canister light.