This is speciacally designed to work with the Uwell Valyrian Pod Kit as a spare or replacement pod tank cartridge.
It comes as a single piece and without coils, if you need to stock up on those you can find them here.
Uwell have put much emphasis into the pod design of their prize pod kit, featuring a slide-top refilling with leak resistant protection, still allowing the fill port mouth wide enough to handle glass droppers. The adjustable airflow on the side is easy to adjust, offering a very restrictive MTL with a 1.0Ω coil or a more airy DTL using a 0.6Ω coil and the vent fully open.
The 3mL capacity is above the standard volume found in pod kits and paired with the 1250mAh internal battery of the Valyrian Pod Kit would last all day for the MTL vapers.