Optics Technology supplies Digital Tharmohygrometer or Digital Temperature and Humidity Indicator. Optics Technology is an ISO 9001:2000 certified company. The Digital Tharmohygrometer has the following technical specifications: Storage temperature -40.0 ...70.0degree C Operation temperature 0.0...50.0degree C Battery type 9V block battery Battery life 8736.0 h Weight 68.0g Dimensions [B x L x H] 89.0 x 120.0 x 40.0 mm