In this photo , showing the prototype and the finished product of the lifeguard, I invented it back in 1984, and is one of the most effective humidifiers on the market . Now sold by Keyser , I made the prototype , and the engineering department at the U of M turned it in to a good solid product. Martin guitars had exclusive rights to selling it as an accessory until we sold the patent to keyser ,it is still considered the best humidifier on the market !