FMA CNC Low Profile 45° Rail for RIS Handguards — Black

CNC-machined aluminium 45° rail mount by FMA, designed to add a diagonal mounting position on RIS, Keymod or M-LOK handguards for AR15 and M4 platforms. Allows tactical lights, laser designators and similar accessories to be fitted at oblique positions without conflicting with primary attachments on the cardinal rails.

The 45° geometry addresses a practical problem: modern handguards are often crowded at the 12, 3, 6 and 9 o'clock positions, where bipods, foregrips and lighting systems frequently compete for space. Moving a torch or PEQ to 1, 5, 7 or 11 o'clock frees up the main positions and keeps the accessory reachable with a natural wrist rotation, without having to cant the rifle. The trade-off is added cross-section: the base introduces an extra layer to the handguard profile, so on already bulky handguards compatibility with the chosen foregrip should be checked before fitting.

The CNC-machined aluminium construction ensures precise Picatinny slot geometry on the top rail, which is essential for mounted accessories to return to zero after removal and reinstallation. Attachment uses 2 screws to anchor the base to the handguard and 4 screws to lock the RIS rail onto the base — a two-stage system that distributes loads and reduces the risk of loosening under recoil.

Key points

• The 45° angle frees the cardinal rails for other accessories, eliminating mounting conflicts on already-equipped handguards.
• Compatible with RIS, Keymod and M-LOK handguards: fits the most common AR15/M4 platforms without additional adapters.
• CNC-machined aluminium delivers consistent Picatinny slot geometry, useful when repeatedly removing and reinstalling a torch or laser while retaining the set position.
• Two-stage attachment — 2 screws for the base, 4 screws for the rail — distributes loads and holds firm under recoil.
• Low profile design reduces radial bulk compared to traditionally built angled rails, and is compatible with holsters and covers that enclose the handguard.

In the box

• 45° mounting base
• RIS rail
• 2 screws for base-to-handguard attachment
• 4 screws for rail-to-base attachment