| Manufacturer | Part Number | Description |
|---|---|---|
| Unknown Manufacturer | ZN1040E | Universal 4 Digital Display Counter |
GEC Plessey Semiconductors |
ZN1040E | Universal Count / Display Circuit |
| Ferranti Electric | ZN1040E | Universal Count / Display Circuit |
| Unknown Manufacturer | ZN1040E-RD | Universal 4 Digital Display Counter |
