TheraTherm electric moist heat packs draw moisture from the air and retain this moisture in a specially designed 100 pct cotton cover. The retained moisture is rapidly heated by high-grade ceramics allowing deeper penetration of heat into the body´s tissue. TheraTherm moist heat packs come with a digital hand control allowing the operator to program treatment temperature, treatment time, and on/off. Programmable timer can be set from 1 to 60 minutes. Temperature can be set from 86 to 166 degrees F. Covers available.