These are Fairchild
CuL9958 Decade Counters
in an 8 Pin TO-5 metal package

These are factory new parts. They have never been installed and have not been recovered from manufactured electronic components.

From the 1969 Fairchild Databook:
The CuL9958 is a complete Decade Counter consisting of four cascaded binary triggered flip-flops modified by a feedback loop to count in the familiar 8-4-2-1 code. Provision is made for clearing and presetting any one of the possible decimal states. The monolithic structure employs only resistors and transistors and is manufactured with Fairchild Planar* Epitaxial process to assure maximum performance and reliability.

 The Decade Counter is designed to operate in the 0° to+75°C temperature range with nominal power supply voltage of 3.3 to 5.5 volts. It is also available inthe -55°C to +125°C temperature range with power supply voltage of 4.0 to 4.4 volts.

 The CuL9985 is available in the hermetically sealed 14 pin Dual In-line ceramic package,
 and in the 8 pin modified TO-5 metal can