... silicone Sizes 15cm,16cm,17cm,18cm,19cm Color Different color can choice Logo Printing Waterproof 3ATM Approve ... &Tourmaline.2)This anion watch can emit negative ions infrared which made you calm,soothe ... fashion design,water resistance(3M)4)Negative ion emittance about 1700-1900 ion/cc5)far infrared ray emittance ... 16cm,17cm,18cm,19cm,1=20cm(circumference)7)color: any colors are available to match well ...