#HTE
Great Design: Butane Refill Canister Caps with Built-In Adapters
Some brands of butane refill canisters have five conspicuous circles on top of the cap:
Those are break-off adapter tips, so that you can refill different brands of lighters.
These have been around for decades, and sadly the original designer is unknown. But I think it’s an example of great design. They spent a little more money on the molds and perhaps pennies in extra plastic to make things easier for the end user.
https://www.core77.com/posts/110529/Great-Design-Butane-Refill-Canister-Caps-with-Built-In-Adapters