3M Peltor | ARC Helmet Rails Attachment Kit, CTVII Version

The P3ADG47‑F SV/2 ARC assembly is engineered for the revised “47‑series” rail interface implemented on COMTAC VII helmet‑mounted configurations. This interface provides updated geometry for improved mechanical stability, controlled pivoting, and consistent earcup sealing under dynamic load.

Selecting the correct adapter is critical to maintaining proper clamping force, rotational articulation, and retention integrity across varying helmet rail geometries.

The Comtac VII and VIII series is designed around the updated “47‑series” rail geometry, which aligns with the P3ADG47‑F SV/2 ARC adapter. Using the legacy P3ADG‑F adapter may appear mechanically functional initially, but it can introduce long‑term risks such as:

• reduced mechanical stability under load
•  inconsistent pivot articulation
• variable earcup seal pressure depending on rail tolerance
• increased likelihood of rail wear or premature component fatigue

For optimal performance and to maintain design‑specified retention and sealing characteristics, the recommended adapter for Comtac VII and VIII systems remains the P3ADG47‑F SV/2 ARC.

*While some customers have successfully used the P3ADG‑F with CT8 units without reporting issues to date, it is important to note that this configuration is not the intended rail interface for the CT8/COMTAC VIII platform.

The P3ADG‑F SV/2 adapter is designed for legacy ARC rail architecture used on earlier COMTAC platforms, including CTXPI and CTXP. This interface maintains backward compatibility with longstanding rail standards prevalent on many existing ballistic helmet systems.

Both assemblies deliver equivalent acoustic, communications, and attenuation performance; the differentiation is strictly tied to rail‑to‑headset mechanical interface design.*