Check the listing for details. Tektronix OTS91C1 ,OTS91L1,CPU. Condition: Used. Listed at 450.00 USD. This sale of 3 cards OTS91C1,OTS91L1,tek CPU CARDS,This unit is used with the Tektronix OTS9100 Series Tektronix OTS91C1is 10Gb Clock/trigger, The Optical Test System OTS91L1 Module is comprised of a 10 Gb/s SONET/SDH transmitter and receiver.