Chronometric Tachometer / Disk Speed Indicator BS Mk15 for Testing Norden Sight F-100 The anchor symbol of the

The anchor symbol of the US Navy appears on the rear of the instrument

and the Turn & Bank Indicators

While flying at the selected limit

and US Navy's PBY5A Catalina and PB4Y Privateer

Chronometric Tachometer / Disk Speed Indicator BS Mk15 for Testing Norden Sight F-100 The anchor symbol of theHere is a WWII era Chronometric Tachometer Disk Speed Indicator Kit, made by Technical Oil Tool Co. (TOTCO), used by bombardiers and technicians to check the proper operation of the Norden Bombsight The kit contains the disk speed indicator, two tachometer tips, instructions, and a metal case with a rubber lined compartment. It is in very good condition given its age. The case measures ~4. 5 inches long, 3 inches wide, and ~1. 5 inches deep.