Offset adapter plate that lets you piggyback a Holosun 407K or 507K K-series red dot on top of an existing scope mount in the 1.9"-2.2" height range. Gives you a fast close-quarters sight alongside your magnified optic without re-zeroing. Compatibility: K-series footprint: Holosun 407K / 507K (and RMSc-compatible micros) Scope-mount height range: 1.9"-2.2" rings/mounts Mounts at a 45deg offset for canted-RDS configuration