These heating mantles are designed for use with round bottom flasks. Features include polyurethane coated aluminum exteriors and a high quality knitted mantle with glass fiber underlay for uniform distribution of heat. Maximum operating temperature is 400°C. Mantles can be used in a wide range of ambient temperatures, from about 45°F to 100°F, and relative humidity up to 80%. The units are not waterproof, and are rated as IP code 10 equipment. Power is controlled (from 0 – 100%) by a knob that is built into the unit - no need for a separate external power control unit. Mantles are designed to securely hold flasks so that the top half of the flask is easily visible during operation. Elements can be replaced easily. An outlet tube is built-in for draining any spilled liquids. A 4-foot long grounded cord is included. Each unit features a fuse that can be easily replaced.