Post WW1 OR's 1920's SD cap https://khaki-on-campaign.webs.com/apps/photos/ Post WW1 OR's 1920's SD cap SD cap Head sizes: Inches or metric 6 3/4" inch = 54cm 6 7/8" inch = 55cm 7" inch = 56cm 7 1/8" inch = 57cm 7 1/4" inch = 58cm 7 3/8" inch = 59cm 7 1/2" inch = 60cm 7 5/8" inch = 61cm 7 3/4" inch = 62cm 7 7/8" inch = 63cm https://khaki-on-campaign.webs.com/apps/photos/photo?photoID=205901426 205901426 SD cap Head sizes: Inches or metric 6 3/4" inch = 54cm 6 7/8" inch = 55cm 7" inch = 56cm 7 1/8" inch = 57cm 7 1/4" inch = 58cm 7 3/8" inch = 59cm 7 1/2" inch = 60cm 7 5/8" inch = 61cm 7 3/4" inch = 62cm 7 7/8" inch = 63cm https://khaki-on-campaign.webs.com/apps/photos/photo?photoID=205901427 205901427