Control Tower BLK with SE Pillar & Quartz Cap Bundle. This version of the widely popular Control Tower features heavier set walls, thicker and larger diameter neck tubing, and a new engraving on the bottom. The Control Tower BLK now comes with a 7mm diameter x 30mm tall pillar stock instead of 6mm. The thicker walls and pillar increase the heat retention making it the superior tower in the industry. Includes a quartz cap and Surface Enhanced pillar for amazing heat retention, surface area evaporation and increased nucleation.