HOBO H8 Dataloggers combine several features commonly found on more expensive units, making them the most powerful, versatile Dataloggers available in this price range. Each has the capacity to store 7944 measurements in 8K of nonvolatile memory and features delayed launch, internal battery check and replaceable battery. One-Channel Temperature Loggers feature a small 4"L wire lead with thermistor that can be used inside or outside the case. Two-Channel Temperature Loggers feature an additional external input lead that accepts a 6'L temperature probe. Records external/internal temperature simultaneously. Four-Channel Temperature Loggers let you measure more! External inputs accept external sensors for temperature, AC current, carbon dioxide, 4–20mA and 0–2.5V DC. No. 125038 stores up to 32,520 measurements. Each requires BoxCar Pro Software, sold separately, for use. Software is compatible with Windows® operating system. Submersible Case available, sold separately.