41mm from the outside and apx. 31mm from the inside.
Steel Bezel w/ Insert For Seiko 6138-0030 6138-0031 Kakume chron blue Tachymeter
omega speedmaster Steel bezel click spring
Steel Bezel Trim Scratch Resistant Bezel Watch Bezel Protections for Watch
Omega Speedmaster bezel+insert 40mm Top-grade best-fit 082SU1589
Omega Speedmaster Bezel Dot Below 70 Authentic
Omega Seamaster bezel click spring 41mm models 2541.80 2531.80 etc..