The HOBO Water Temp Pro v2 is durable with 12-bit resolution. Complete with a precision sensor for +-0.2degrees-C accuracy, this logger measures temperatures between -40degrees-C and 70degrees-C (-40degrees-F to 158degrees-F) in air and up to 50degrees-C (122degrees-F) in water. Its waterproof, streamlined case allows for extended deployment in fresh or salt water. Moreover, the Water Temp Pro v2's optical USB interface makes it possible to offload data even while the logger is wet or underwater. A solar radiation shield is required to obtain accurate air temperature measurements in sunlight (RS1 Solar Radiation Shield, assembly required; or M-RSA pre-assembled Solar Radiation Shield). IMPORTANT: This HOBO data logger requires HOBOware software and a communications device.