High-quality sauna hourglass exclusive from SudoreWell (high-quality sauna accessory) made of solid beech wood. Easy to read 15 minute scale Green sand glass cylinder. Easy to see even in dark light. Sand is a natural product. Each sand grain is shaped differently. Therefore, it is difficult to specify an exact runtime for hourglasses. Tolerances of up to 2 minutes are unfortunately not to be avoided. Normally, however, they move under 1 minute. There may be several sand grains blocking each other at the passage point. Simply tap lightly against the glass or twist the hourglass to remove the blockade. Under certain climatic conditions, a light film can form on the inside of the glass cylinder. This is not a production defect but a natural appearance due to static charging. For all hourglasses, the glass is glued with a heat-resistant special adhesive. This significantly reduces the risk of breakage.