Silicone Sport Wristbands Replacement Strap with Buckle for iWatch Series. Adjustable Buckle Ocean Watchband 49mm Silicone Ocean Strap Watch Band for Apple Watch. The Ocean Band is moulded in a thick silicone material with a tubular geometry allowing it to stretch for a perfect fit, even over a wetsuit. The steel buckle and adjustable loop secure the band. The Ocean Band are designed for Apple Watch Ultra and pair best with the 49mm case size. The bands are also compatible with 49mm, 45mm,44mm, 42mm, 40mm, 38mm cases. Regular Bands fits 130-200mm wrists water/sweat resistant. The steel buckle and adjustable loop secure the band. Soft & smooth silicone feeling. Compatible with: apple watch3 8/40/41/ 49/45/44/42mm. Premium material.