Remington Accessories Model 500 Wireless Mini Dehumidifier (19946) This compact unit attracts and holds moisture through water crystal technology to protect gun safes and cabinets from excessive moisture within a 500 cubic feet enclosure. No batteries or electricity necessary. Works for up to 10 years. Features: – Protects against excessive moisture within 500 cu. ft. of enclosed space – No battery or cord needed – Works up to 10 years – Non-toxic and eco-friendly – child and pet safe