Rusan Q-R adapter M52x0.75 for Ø50 mm (ARM52-50)

What it is and what it is for
The RUSAN ARM52-50 is a clamp-style Q-R adapter intended to attach night vision and thermal clip-on devices to the objective/tube of a riflescope with a 50 mm external diameter.

Key characteristics
The adapter uses an M52x0.75 thread interface and this variant corresponds to the ARM52 size for a 50 mm objective. The manufacturer lists a weight for the ARM52 series of 0.164 kg. The upper part that couples the NV/thermal device is described in the official documentation as made from an aluminium alloy.

Compatibility
The ARM52 series is suitable for many clip-on units; examples cited in the catalogue include Liemke Luchs 1 & 2, Liemke Merlin 35, Night Pearl Seer, Cono Seer, Leica Calonox 2, Guide TAxxx, Burris BTC, JSA, Nitehog Viper, Steiner Nighthunter C35, Lahoux Clip 35 & 50, among others.

Usage notes
For specific clip-on units and scopes the complete assembly requires combining the M52 adapter with reduction rings starting from the M52x0.75 thread; the exact combination depends on the clip-on model and objective diameter.