2100mAh. That's lower than the straight 20A batteries, which hold 2500-3000, depending on which. That is also the exact tradeoff. As ampacity increases, capacity decreases. I linked you to some independent tests about the batteries. The Sony VTC4s are native 20A batteries, but which will withstand discharge currents up to 30 amps without dangerous overheating. They are, IMHO, the best available compromise between battery life and ability to withstand high currents. I use them exclusively in mechanical mods and two-battery mods where I intend to vape over 100 watts. I am willing to use the LG HG2s in my RX200 mods because they are three battery mods, lowering the current per battery to produce maximum wattage due to higher native voltage. That is the first time I ever bought any vape batteries that were not VTC4s. So let me repeat: If you are going to vape a two battery mod over 100 watts, or a one battery mod over 60 watts, then use the VTC4s. If you intend to stay under those numbers, any of the above 20A batteries I listed will be fine. I understand the supply problem you endure and I am sympathetic. But the bottom line here is we're talking about a law of physics as it applies to your personal safety. That I can not change. I can recommend the RX200 mod; I have a pair of them and I feel quite comfortable using the HG2s in them. But in all my mech mods, and most of my regulated mods, one and two battery, I run VTC4s. Let me suggest you use the second link I offered to determine, by your likely usage which you should know from your existing vape, just how much ampacity you will require in the mods you are considering purchasing. From there, if 20A batteries are adequate, you can use any of the other batteries without worry and you don't have to bear the expense and lower capacity of the VTC4s. If 20A batteries are suitable for you intended usage, then buy the LG HG2s, or the Panasonic 30Qs, or the AW 20A 3000mAh batteries-- whichever you can get at the best price-- for the longest possible battery life, or any of the other batteries I named for the same ampacity and somewhat shorter life (and usually a better price).