It’s an 18650 battery cover. So, if you’re using 3 AAA cells, you won’t be needing this. But if you have an 18650 rechargeable cell, the plastic tube makes for a tighter fit.
It’s an 18650 battery cover. So, if you’re using 3 AAA cells, you won’t be needing this. But if you have an 18650 rechargeable cell, the plastic tube makes for a tighter fit.