Opening in the middle is 10 mm on the end links
Crown Stem Gear for Seiko 6117-6410 6117-6419 Worldtime indicator ring inner bezel
One Hour Hand with Lume
the watch is not included only for reference
Bracelet and Watch are not included
Sanded Sapphire Blue AR 320w34ga Seiko diver 6306-7001 7548-700C 7548-7000 Opening in the middle isReplacement New Sanded Sapphire Glass crystal for Seiko case models listed below. This is a SANDED SAPPHIRE CRYSTAL WITH BLUE AR COATING. We also have with Blue AR coating non sanded. Please see our other listing for Sapphire with Blue coating eBay ,Item ID: 223490478484 It is an exact fit for your Seiko 6309: 6309 7040, 6309 7049, 6309 7290, 6309 729A, 6309 729B 6306: 6306 7000, 6306 7001, 7548: 7548 7000, 7548 7009, 7548 700A, 7548 700B, 7548 700C,