Use the Oasis HumiGel Replacement Kit to refill your Oasis in-case guitar humidifier system, and keep your acoustic guitar in premium condition. Improper case humidity is the number one cause of damaged acoustic guitars, causing wood to split if it's too dry and causing warping when it's too humid. HumiGel absorbs up to 500 times its weight in water, making sure your guitar case is never too humid. Use it with the Oasis humidifier system, and your case will always be a safe environment for your guitar. One Oasis HumiGel Replacement Kit will give you years of refills.