A student turned me onto these wonderful Oasis Case Plus + humidifiers ($16.95 free shipping in North America – ADD $6.00 INTERNATIONAL SHIPPING CHARGE [BELOW] FOR ORDERS OUTSIDE THE US/CANADA). Lack of humidity causes terrible damage to guitars. My favorite feature of the oasis case plus + humidifier ($16.95 free shipping in North America – ADD $6.00 INTERNATIONAL SHIPPING CHARGE [BELOW] FOR ORDERS OUTSIDE THE US/CANADA) is you can see when the unit needs a refill (see the empty unit above). These oasis case plus guitar humidifiers oasis ($16.95 free shipping in North America – ADD $6.00 INTERNATIONAL SHIPPING CHARGE [BELOW] FOR ORDERS OUTSIDE THE US/CANADA) have rapidly replaced the cumbersome Damp-it brand guitar humidifier in my gig bag. The Dampit guitar humidifier is much messier, as it is difficult to keep from getting excess water in your guitar. The oasis guitar humidifier is a tidier unit and at ($16.95 free shipping in North America) I can afford to keep one in all of my guitar cases. Ed Eastridge While the original Blue Oasis Case humidifier ($16.95) 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 device. For this reason, we have developed the Oasis Plus+ humidifier ($16.95 free shipping in North America– ADD $6.00 INTERNATIONAL SHIPPING CHARGE [BELOW] FOR ORDERS OUTSIDE THE US/CANADA) . The Oasis Case Plus+ is the same size and shape as the original blue Oasis humidifier, but is made of a different material which provides 50% more humidity output. This humidifier is designed for use in drier environments where the relative humidity is below 25%. The Oasis Case Plus+ humidifier $16.95 free shipping in North America– ADD $6.00 INTERNATIONAL SHIPPING CHARGE [BELOW] FOR ORDERS OUTSIDE THE US/CANADA), like the Oasis Case humidifier, uses two powerful small magnets, which are embedded in the seam of the humidifier, to attach to either a small sticky backed piece of stainless steel or a metal clip (both are provided with the humidifier). The Oasis Case Plus+ humidifier can be used in woodwind and stringed instrument cases such as clarinet, violin, cello, guitar or mandolin. Oasis Case Plus+ humidifier OH14$16.95 International Shipping ChargeAdd this charge for any item with (Free shipping in North America) going outside the US or Canada. International Shipping Charge ISC101$6.00