You can find the Aspire K4 kit here.
The Aspire K4 starter kit doesn’t come with a 0.4ohms coil, it comes with two 0.27ohms one installed in the tank and one in the box. I wouldn’t recommended using the 0.4ohms or 0.2ohm Cleito coil for the K4 kit just because the battery is pushing out a set power output that was geared toward the 0.27ohms coil.
The rubber cap on top of the Cleito tank is a insulation piece so that user don’t burn their lips when the tank gets hot.
The Aspire K4 starter kit is a great on the go subohm kit.