The band of the AP9009 retrofit kit is made of Fluororubber. The overall case is made of 316L stainless steel carefully manufactured polished by CNC machine tools. The buckle is also made of 316L stainless steel. Silicone stickers are included inside the case to avoid scratching the Apple Watch. You will be amazed by the overall quality and style of the AP9009 retrofit kit. BAND MATERIAL Fluororubber CASE MATERIAL 316L Stainless Steel BUCKLE MATERIAL 316L Stainless Steel BUCKLE TYPE Pin Buckle BAND FITS WRIST 150mm – 220mm COMPATIBILITY MODELS Apple Watch Series SE/4/5/6/7/8/9/Ultra/Ultra 2 COMPATIBILITY MODELS CASE SIZE Apple Watch 44mm/45mm/49mm KIT WEIGHT 75 Grams BOX INCLUDE AS FOLLOWS 316L Stainless Steel Case x 1 Fluororubber Band x 1 Stainless Steel Buckle x 1 The Apple Watch appears in the product picture only to better show the retrofit kit compatibility, product excluding Apple Watch. The AP9009 Retrofit Kit doesn’t affect the water resistant of the Apple Watch.