Yes they were the battery power outlet of choice in the 50's and 60's until the flawed adoption of cigar lighter sockets for such. My series LR has them for optional inspection lamp. Matching double plugs are still available.

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Richard

2018 Roadster 3.7
1966 Land Rover S2a 88
2024 Royal Enfield Guerrilla 450
1945 Guzzi Airone