20mm Blue Premium-Grade Vulcanized Tropic Rubber Watch Strap For Seiko Divers and other Divers WaterproofContemporary, durable and incredibly comfortable. Moulded from swiss grade Fluoro Elastomer (FKM) rubber typically used in the aerospace and aviation industry for class leading durability. Excellent resistance to UV rays, extreme temperatures, mechanical stresses, chemicals, and seawater. Strap is non toxic, non marking, non allergen and does not attract dust. We calibrated a subtle thickness tapering for wear comfort as number one priority. Please