MY ATN X SIGHT HD 5-20 CAME WITH AN ADDITIONAL INFRA-RED TORCH ATTACHMENT , BUT I CANT WORK OUT WHICH BATTERY TO USE ?

ANOTHER OF THEIR LIGHTS USES AN INR 18650 , LIKE A 2X AA , BUT FATTER , SO I ORDERED TO FROM A SUPPLIER , BUT THEY ARE TOO THICK TO BE INSERTED , ANY IDEAS FOLKS


Chris