Just use the 2 screws provided to install it . Wall-mounted Align the additional wooden mounting strip vertically, screw it into the pre-drilled hole, and hide the mounting strip perfectly behind the hourglass machine. 15 minutes-the popular length of time to enjoy sauna. It also includes 5-minute and 10-minute approximate markers for shorter sessions. The sand timer is suitable for use in the sauna room, allowing you to monitor the fixed time interval of 15 minutes. Accuracy-accurate to within . The hourglass is fixed in place with high-temperature adhesive and small metal fasteners. It is best to install the timer opposite the heater and control it by simply rotating it. Even if it is used for a long time, the accuracy of the watch remains unchanged because of the uniform granularity of the annealed and screened sand.