25mm diameter
Holds 21700 and 20700 batteries
Now comes with dragon button 
Atomizer not included
Two position full Copper switch for maximum conductivity
No tools required
No adjustments needed
Large vents for safety
Lifetime warranty as always
 
Please note this is a mechanical mod. A great understanding of Ohm's law and battery safety is needed. If you do not have a great understanding of either of those please do not purchase this product.