If you want to buy the 2ml replacement glass tube, here is the link for your reference
If you want to buy the 4ml replacement glass tube, here is the link for your reference
https://online.aspirecig.com/aspire-cleito-replacement-pyrex-glass-tube-p-176.html
Before using the Athos tank or a new coil for the first time, ‘prime’ the coil by adding e-liquid drops on the cotton first, install the coil into the tank, then fill the tank and stand it upright for 5 minutes. This will avoid burning the coil.
Know about Athos tank, please check: https://aspirecig.com/

