Sylvan Arms Arh400-R Gen4 Folding Stock Adaptor Black

The Sylvan Arms ARH400-R Gen4 folding stock adapter transforms your AR-15 into a genuinely packable rifle without sacrificing shootability. If you haul gear cross-country, hunt from a truck bed, or simply need your rifle to fit tight spaces, this adapter lets you fold the stock down and shrink your overall footprint significantly. The Gen 4 design sits closer to your lower receiver, cutting excess length and the gap that plagued earlier generations—the result is a compact, field-ready setup that doesn't feel compromised.

Built for the hard use that comes with overlanding and remote hunting, the adapter is lightweight and corrosion-resistant, so it won't add bulk or rust out in wet conditions. Installation is straightforward on standard AR-15 lowers, and the right-fold option (this model) suits most shooting positions and pack configurations. Whether you're squeezing your rifle into a truck cab, a travel case, or a backpack, the ARH400-R folds quickly and locks securely when deployed.

This is not a gimmick—it's a practical solution for hunters and shooters who move their rigs frequently and need to minimize space without compromise. Pair it with the right stock and you've got a rifle that works as hard in the field as it does in your vehicle.

Key Features

• Folds to significantly reduce rifle length for compact storage and transport
• Gen 4 design positioned closer to lower receiver to minimize gaps and overall collapsed length
• Lightweight construction keeps your rifle's balance uncompromised
• Corrosion-resistant finish withstands field conditions and extended storage
• Right-fold orientation for versatile shooting and carry positions
• Compatible with standard AR-15 stocks (1-3/16" x 16 thread)

Specifications

Frequently Asked Questions

Will this folding stock adapter work with my AR-15 lower?

Yes, the ARH400-R Gen4 is compatible with AR-15 lowers that use the standard 1-3/16" x 16 thread stock interface. If you're unsure whether your lower uses this thread pattern, check your rifle's manual or ask us at the counter.

How much does the rifle shorten when the stock is folded?

The exact reduction depends on your stock length, but the Gen 4 design positions the adapter closer to the lower receiver to maximize compactness and minimize gaps compared to earlier generation folding adapters.

What is the right-fold orientation, and does it matter?

Right-fold means the stock folds to the right side of the rifle when collapsed. This configuration works well for most right-handed shooters and commonly accessed pack positions, though your specific preference may depend on how you carry and shoot.

Is the ARH400-R Gen4 corrosion-resistant?

Yes. The adapter is built to resist corrosion, making it suitable for wet field conditions and extended storage without rusting or degrading.