OH-5:

While the original Blue Oasis^® provides sufficient humidity in many environments, it is not effective everywhere. The humidity demands of the desert, mountain states or frigid north exceed the humidification capacity of the OH-1. For this reason, we have developed the OH-5 Plus+ humidifier. The OH-5 Plus+ is the same size and shape as the original blue Oasis^®, but is has a different liner which provides 50% more humidity output. Because the OH-5 Plus+ is the same size as the original Blue Oasis^® and it has 50% greater humidity output, it will be necessary to refill the Oasis^® OH-5 Plus+ more frequently than the original Blue Oasis^®. Use the OH-5 when the environment outside the case has a relative humidity of 25% or less. Each OH-5 comes with a stabilizer bar for mounting the OH-5 humidifier and a 10 cc syringe for distilled water filling control.
Because tap and bottled water have dissolved minerals that can clog the liner, distilled water is recommended to extend the useful life of your humidifier.

OH-2:

The OH-2+ is the latest version in the OH-2 hygrometer product line. It has a new digital sensor that improves the accuracy of the hygrometer to +/- 3% between 20% - 80% RH. The hygrometer also has an extended reading range down to 10% RH rather the 20% RH on the previous two models. This eliminates the annoying "LL" sign on the display when the humidity drops below 20% RH. The increased range will help those users in extremely dry areas to get a more accurate reading of their humidity. The humidifier has the same size and look as previous versions. The calibration feature is also included, but shouldn't be necessary with the improved accuracy.
Don't forget the OH-20 hygrometer holder that allows you to place the hygrometer near the sound hole for accurate RH readings.

Features
• Measures temperature in degrees C or F with the range of 32-125 degrees F
• Min-Max memory for both humidity and temperature
• For indoor use only
• Uses a CR2032 battery
• Accuracy +/- 3% between 20-80%