On the link I put above it says:
"Setting new standards for TPD compliant atomizers, the Aspire Cleito Exo Tank combines a rugged, ready-for-action look with simple functionality. With no airflow adjustment, the Exo is pre-tuned for moderate sub-ohm vaping in the 60 to 100 Watt power band. With the pre-fitted Exo coil, this tank will hold 2ml of e liquid. The 23.5mm diameter Exo tank is also compatible with Aspire’s standard, slimmer Cleito coils.
The Exo tank comes with a fitted 0.16 Ohm coil, and a spare to see you through your first few weeks of vaping. Exo coils are fatter than the standard Cleito coils. The great thing about the Exo is that the coil threading is 100% compatible with standard Cleito coils. Fitting a standard Cleito coil in the Exo tank actually increases the tank’s e liquid capacity by about 1.5ml.
As well as giving the Exo atomizer a rugged, functional look, the stainless steel tank sleeve also offers the Pyrex glass a high level of protection. The e liquid level is still clearly visible through the stylish sleeve cutaways. Special ports at the top of the sleeve channel air down to the Exo coil. The top-airflow design cools the tank and ensures leak-free vaping. "