Chronometric Tachometer / Disk Speed Indicator BS Mk15 for Testing Norden Sight F-100 and US Navy's PBY5A Catalina

and US Navy's PBY5A Catalina and PB4Y Privateer

type AN-5825-7

and the Turn & Bank Indicators

the level indicator contains fluid and the metal ball

A Yellow (Minus Blue) filter is attached

Chronometric Tachometer / Disk Speed Indicator BS Mk15 for Testing Norden Sight F-100 and US Navy's PBY5A CatalinaHere 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.