| NC2opt01 | Military version in compliance
with MIL-E-5400T Class 2 (add suffix M) |
| NC2opt02 | TTL control "High" is on (add suffix T) |
| NC2opt03 | Inverted TTL control "Low" is on (add suffix IT) |
| NC2opt04 | 14-pin instead of 24-pin package
(NC2201 - NC2601 models only) |
| NC2opt05 | +12 VDC operating voltage
(instead of +15 VDC) |
| NC2opt06 | Custom screening available consult factory |