It's my own design. I did three models - a standard diver, a GMT model, and this Chrono. Posted about them here > naddr1qvzqqqr4gupzqry7tctlhh64tm6pmteu8gvkwjwgfruu0yvkduc04e0ycpyqapctqy2hwumn8ghj7un9d3shjtnyv9kh2uewd9hj7qgwwaehxw309ahx7uewd3hkctcpzamhxue69uhhyetvv9ujuurjd9kkzmpwdejhgtcqra8kxetpdck5g6tkv4ez64mpw33kst2jv4mxjeth9468gvr6d9nqh2hne4