product details Metal material: zinc alloy; Gem material: acrylic; Ring size: 17 mm (opening can be adjusted) Delivery quantity: 9 pieces Features: change color with temperature, black below 14 degrees, change color between 14 and 37 degrees, One ring can change all colors, and more than ten colors can be changed into adding gradient colors, specific personal experience; Precautions: 1. The dry temperature range that the ring design can withstand is 0-38 degrees, Avoid exceeding the maximum temperature set by the ring, which will damage the discolored material; nbsp; 2. Avoid hot water (because the discoloration interface is epoxy cover, it will damage the discoloration material when exposed to high temperature At the same time, it will produce thermal expansion and contraction effects , resulting in damage to air and water; nbsp; 3. Avoid knocking yourself. We will do our best to provide you satisfactory service