LINEAR INDICATOR: Chessel Ltd, manufacturers of laboratory and industrial process chart recorders, has introduced the Series 700 ... of 6 ata, is now available from Elkay Electrical Manufacturing Co Ltd. Designed for 2, 3 or 5-way 2.5mm- cable, it is housed in either Nylon 66 or Noryl. ... Audio and video signals are transmitted to the surface via a small ia#39;m diameter cable. ... a pistol grip handle and can be easily removed from the divera#39;s helmet underwater for hand- held operation.