Rubber Strap for Longines® HydroConquest 39mm black dial & blue bezel (2026)Not Just Rubber. FKM Rubber. We use FKM vulcanized rubber, the same material trusted in aerospace and motorsport. It resists heat, cold, UV rays, solvents, and sweat while maintaining its softness and flexibility over time. It is also anti allergic, making it safe and comfortable for all skin types. No cracking. No fading. No compromise. Precision Fit. Lightweight comfort. Every ZEALANDE strap is made to fit your watch like a second skin. We use a