Cantilever Mount

Rather than clamping directly above where it sits, a cantilever mount's ring extends forward on an arm from the clamp point, positioning the scope's ocular lens at the correct eye-relief distance even when the only available rail space is further back than a standard mount would need.

This is especially relevant on carbine-length handguards where rail real estate is limited, letting a magnified scope sit properly forward without needing an unusually long rail section — a detail borrowed directly from real-steel optics mounting practice rather than an airsoft-specific invention.

Checking a scope's specified eye relief distance against the cantilever offset a particular mount provides is worth doing before buying either separately, since mismatching the two undoes the whole point of choosing a cantilever design.