Flashlight adapter for 18650

This is a great tiny cheap flashlight that I've bougth on Aliexpress. Unfortunatelly the battery they provide lasts like 10 minutes.
I've made an adapter that enables putting a 18650 battery inside.
To connect both pieces of the casing use a piece of cable and put it into the tube that goes along the adapter.
Note that after adding this extension the flashlight is not water resistant anymore.
https://aliexpress.com/item/1005005389166874.html