Vaportek Ez-Disk refills are designed for the Vaportronic and Ez-Twist systems. The Ez-Disk utilizes a special, non-woven fiber to release an effective neutralizing dry vapor into the air. One disk treats 2,000 cubic feet. Ez-Disks are spill-proof, non-toxic, and biodegradable. Disks are rated for up to 30 days use. Ez-Disks are available in 19 fragrances. Please refer to the Fragrance Guide for details. For odor control, the Classic Neutral is the best option.