A blunt needle tip is essentially a bottle cap with a built in stainless steel needle point. People typically purchase this item to (re)fill e-juice cartridges or tanks that have small fill openings that a normal bottle nose has trouble fitting into.
How to Install A “Blunt Needle Tip”
First, depress the child safety lock by pressing down the bottle cap, then twist counter-clockwise while still keeping the bottle cap pressed down until the bottle cap is loose enough to pull off. Now that you have the bottle cap off, use your thumb to pop off the bottle nipple by pressing against the bottle nipple top with the tip of your inner thumb, as if you are trying to roll the bottle nipple off the bottle with the tip of your thumb. Now that you have the bottle cap and bottle nipple off, you can screw the blunt needle tip on. This cap does not have a child safety and can simply be twisted on by placing the bottom of the tip onto the top of the bottle, aligning the blunt needle tip thread with the bottle thread and twisting clockwise until the blunt needle tip fits snugly on the bottle. There is also a rubber accessory built onto the blunt needle tip which can be placed over the stainless steel tip to prevent leaking, and help keep the blunt needle tip sanitary.
Purchase your blunt needle tip here.