Eaton's MIL-DTL-38999 Series IV accessories extend the service lives of military and aerospace connectors and cable assemblies by providing protection from contaminant intrusion, electrical and mechanical damage, and repeated engagement cycles.
| Designator Type | Eaton | Description |
| Cover Type | RC | Receptacle Cover |
| PC | Plug Cover | |
| Finish Class | C | Anodize, -65°C to 200°C (-85°F to 392°F) |
| F | Nickel per ASTM B733, -65°C to 200°C (-85°F to 392°F) | |
| G | Nickel per ASTM B733, -65°C to 200°C (-85°F to 392°F) | |
| K | CRES (Passivated), -65°C to 200°C (-85°F to 392°F) | |
| N | Nickel Plate per ASTM B733, -65°C to 200°C (-85°F to 392°F) | |
| S | Electrodeposited Nickel, -65°C to 200°C (-85°F to 392°F) | |
| T | Nickel Fluorocarbon Polymer, -65°C to 175°C (-85°F to 347°F) | |
| W | CAD/OD per QQ-P-416, -65°C to 175°C (-85°F to 347°F) | |
| Y | Passivated per SAE-AMS-QQ-P-35, -65°C to 200°C (-85°F to 392°F) | |
| EMI Codes | G | EMI grounding, Receptacle Covers Only |
| O | No EMI Grounding |