As stated, I’m ordering an FFL X4 Stellar. It comes with a 21700 flat top cell. I have tons of Samsung 18650 batteries and button top style adapter tubes. I saw online that FFL lights are recommended to only use flat top and not button top. I have Sofirn and wurkkos lights that are 21700 flat top and the adapter and 18650 work flawlessly. So would the button top adapter and 18650 put too much strain on the FFL springs? Here’s a pic of the adapter for reference.
by mrregina
