M4A1 carbine assault rifle with a top-mounted optic – Custom 3D Printed Miniature Accessory Parts Pieces for Brick Block Figures

It is modeled after an M4A1 carbine and features:

• An adjustable stock.
• A pistol grip.
• A magazine.
• A railed handguard. Unlike some of the previous versions, this one does not have a vertical foregrip or any visible side-mounted accessories like a laser or light module.
• An optic sight mounted on the top rail, which appears to be a red dot sight, possibly with a magnifier or a larger enclosed reflex sight.
• A standard triangular front sight post.
• A barrel with a flash hider.

This is an accessory for toy soldier minifigures, representing an M4A1 carbine with a top-mounted optic, but a more streamlined handguard setup compared to some of the other models you’ve shown.