Posts 479 Likes 1,548 MoclovFlop ·Dec 15, 2020 Got one. Thanks folks Looking for a Certina screw down crown commonly seen on the Ph200m. Measures 6.4mm diameter by 4.5mm tall , and should be stamped Mulco on the back seal ring. Reference image borrowed from shucktheoyster: Thanks in advance! Edited: Jan 20, 2021