... ,water-proof and rust iButtons, TM Card(iButton) is sealed with stainless steel (su304-0.3), sturdy & durable, rust-resistant and ... made of heat-resistant resin with a good seal performance, aging-resistance, moisture resistance, heat-resistance.diffeent bracelets are available.Main features ... ¡ãCWater proof.Dimension: 16.25mm*5.89mm (max) iButtons DS1990 with bracelet