SummarySeahorse Clock should accept any single battery clockworks. Opening is 80mm. Model is in several pieces to be glued together after printing. The seahorses, the barrel, the base, the dial and the disk. Disk is printed upside down and is flipped over and glued to barrel. Dial is glued to disk.. Glue seahorses to barrel and base at the same time to insure correct alignment. Attach clockworks to finish project. I find this method preferable because of the shorter print times for each part, and the ability to have multiple colors on the finished assembly without painting.