The Uwell Caliburn A2 and A2S replacement pod cartridges are completely compatible with all devices the A2, AK2 and A2s. The filling method and resistance is different the A2 is 0.9ohm while the A2S is 1.2ohm. They both come 4 pods per package so try them both. As pictured the A2s are clear with a rubber stopper on the top fill system.
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Uwell Caliburn A2 0.9 ohm Replacement Pod
Specifications
Capacity: 1.8ml
Material: PA, Aluminum Alloy
Uwell Caliburn A2S 1.2 ohm Replacement Pod
Specifications
Capacity: 1.8ml
Material: PA, Aluminum Alloy
It Includes:
4x Uwell Caliburn A2 0.9 or A2s 1.2 ohm Replacement Pod
1x User manual