As mentioned, the U50 is 41mm across, https://www.arelogios.cz/categoria-do-produto/panerai/ 11.15mm thick, and 47mm lug to lug. Lug width is 20mm, and the U50 has drilled lugs (woohoo!), making strap changes https://www.rmorologi.cz/Collezione/rm-40/ nothing https://www.aklockor.cz/Kollektion/hublot/ short of a breeze. Inside that now smaller case and covered by a solid case back, Sinn has fitted the U50 line with Sellita's SW300-1, a Swiss-made automatic movement with a date function. The SW300 is meant as direct competition for the higher-end expressions of ETA movements like the 2892-A2.