I've noticed a lot of people, including vendors, market all these carto tanks as "DCT". What's the difference between a dual coil tank and a single coil TANK? There's just a tube & 2 end caps. I think calling it a DCT just makes things confusing for newcomers. Most of us use single coil cartos in these "dual" coil tanks, so why do we call them DCTs?.. Just kinda venting + bored. That is all