We offer Time Recording Devices. Pi 130 labotech all mains a.c. Time clock: permitting time marks at intervalsof 1, 5, 10, 30 or 60 seconds at reached low voltage to run time marker. pi 131 direct writing time marker : a.c. Mains , range 15 secs. & 1 secs. pi 132 direct writing time marker : a.c. Mains, range 5 secs. & 30 secs. pi 133 direct writing time marker : a.c. Mains, range 5 secs .& 30 secs.pi 134 tuning fork n- 100 : with stylus. pi 135 electrical n- 100 tuning fork : to work on 4v. Dc. pi 136 electrical time marker : signal marker, double magnet.pi 137 electricaltime marker : double lever, for marking time & event or two time intervals. pi 138 two way kymograph time marker: twin lever for use with any kymograph .pi 139 vibrating reed : vulcanite base , adjustable contact intervals of 5, 7, 10, 15, 20, or 30 per sec.pi 140 vibrating reed: vulcanite base, adjustable contact intervals of 5, 7, 10, 15, 20 or 30 per sec. Are electromagnetically maintained.