A handmade 30 minute sandglass by Hightide. Also available in 3 min / 5 min / 15 min. Dimension: (Φ)3.7" x (H)6.7" Hourglass Product Information & Safety Instructions Only the Clear color features black sand. The Amber, Blue, and Green versions all contain white sand. This product is handmade, so the measured time may vary. Please use it as a general time indicator only. The standard tolerance is ±20 seconds, but the actual measuring time may vary depending on the environment in which the product is used. If you require precise time measurement, this product is not recommended. Because each piece is handmade, slight variations in shape and color may occur. Usage & Safety Instructions Always place the hourglass on a flat, level surface. Do not use or place it on unstable surfaces. This product is made of glass and is fragile. Please handle it with care. Do not shake, throw, or subject the product to strong impacts, as this may cause it to break. If you notice any cracks, chips, or other damage, discontinue use immediately. Due to its delicate handmade construction, the product may be damaged by sudden changes in temperature or air pressure. Do not use it in a sauna, bathtub, or near open flames or other heat sources. Occasionally, you may notice a few black grains mixed in with the white sand. This is normal and does not affect the quality or performance of the product. Keep out of the reach of young children. Store and use the product in a safe place.