Split action timers, as follows:
<ul>
<li>Semikrograph -- 1/50 second recorder, with split action; one revolution in 6 seconds; 3 minute register; running time of one hour
<li>Reference 550 -- 1/10 second recorder, with split action; one revolution in 30 seconds; 15 minute register; permanent motion; 15 jewels; incabloc shock-protected; valjoux 57</li>
<li>Reference 572 -- 1/10 second recorder, with split action; one revolution in 30 seconds; 30 minute register; 15 jewels; "stop and go on" by right pusher; split action by left pusher; reset by crown when hands stopped</li></ul>