The worlds best vertical cartridge and e-cig juice tank storage solution. 510 thread compatible, designed to secure all THC cartridges and E-Cig Juice Tanks. No more tipping over. Never play balancing games with your tanks or cartridges ever again. Stop spills, leaks, tip overs, lost cartridges and draped oil before they ever happen. Screw in, Secure, Upright. Originally designed to simply keep cartridges vertical and out of kids reach, it was quickly determined it had so many extra benefits. So we made a larger model to comfortably handle Juice Tanks. Hand crafted with quality and care in America. The line of Keepers are simple and will always do their job.