Update 23 April 2026
Maximum speed and precision for attaching the Calonox Sight and Calonox Sight SE, and the new Calonox 2 Sight and 2 Sight LRF to your scope, with the MODULAR ADAPTER by Rusan
Disclaimer: Thermal clip-on viewers such as the Leica Calonox Sight are observation instruments of common purchase, ownership and use, which can also be used in combination with a pointing scope through an adapter. When used in the latter function, they are suitable for night shooting. We recommend in the latter case to respect the prohibition of hunting outside permitted hours and to limit use to pointing within the limits of control and harvesting activities permitted by law.
From observation to aiming with the Rusan one-piece adapter.
We discuss the adapter for the Calonox Sight because it is perhaps the best thermal clip-on viewer on the market, especially because it allows you to observe with the quality and comfort of a purely observation viewer, while being designed to be a perfect clip-on to apply to the pointing scope. When you are engaged in night control activities, it is very convenient to be able to observe animals with the Calonox Sight, and then apply it to the objective of the pointing scope when needed at the moment of shooting.
To switch to aiming mode, simply unscrew the eyecup and screw the adapter in its place to attach the Calonox to the objective of the scope, any scope of any brand, an operation that can be done easily even in the dark.
The adapter slips onto the objective and is fixed simply by closing its locking lever with a finger. The large buttons in the center of the top part of the Calonox then allow you to position the instrument well centered with respect to the scope (a necessary condition to see the scope’s reticle with the crosshairs perfectly straight), simply with the tactile sensation of having them in line with the scope itself.
The only additional precaution required before aiming is to press the menu button and disable the “handheld” function which activates instead to expand the screen if you wish to observe. An operation that, if tried a few times to familiarize yourself, takes about 5 seconds.
The Rusan adapter is made of metal, manufactured with diameter dimensions that vary by 1mm or even less from one model to another, to ensure perfect compatibility with any pointing scope. The quality of materials and workmanship result in an adapter that guarantees a granite-like, highly precise and extremely stable assembly of the Calonox attached to the scope. Multiple tests have been performed with dozens of shots, even removing and reinserting the Calonox with the adapter on the scope objective, without the point of impact changing by more than 1 cm at 100 meters.
Here is a video showing how the Rusan adapter works
The adapter for the Calonox Sight is imported by Forest Italia and costs €170 (€180 for the Calonox 2 Sight), VAT and shipping included. It can be ordered directly here, for information info@forestitalia.com – 045 8778772. When ordering, it is recommended to provide the model of the pointing scope to be associated with the Calonox Sight.
For those who need faster transition from observation to aiming, it is possible to further reduce the times by observing without the eyecup, which does not create any problem with image quality, or even with the Rusan adapter already screwed onto the Calonox eyepiece, in which case the eye will be forced to stay slightly further from the eyepiece itself, but without compromising its observation functionality.
Maximum speed and precision for connection, with the MODULAR RUSAN ADAPTER.
Rusan has produced a two-piece modular adapter that offers three advantages compared to the standard one-piece model.
How the modular adapter works.
The Rusan modular adapter is composed of two parts: a ring called MCR-M52 that screws onto the eyepiece of the Calonox Sight (or Calonox 2 Sight, in which case it is called MCR-M43) and which can remain screwed onto the eyepiece even during observation, and the rest of the adapter that slips onto and fixes to the objective of the scope (and is therefore identical for both Calonox Sight and Calonox 2 Sight), it is called MAR-.. (dots represent the external diameter of the scope onto which it is mounted), closing with a finger the appropriate lever once the adapter is fully inserted, ensuring it is centered with the white arrow at 12 o’clock relative to the scope objective.
To use the Calonox for observation, the Rusan ring screwed onto the eyepiece certainly does not offer the comfort of the soft Leica rubber eyecup, but compared to the one-piece adapter it allows you to keep your eye at the optimal distance from the lens.
The attachment of the Calonox to the optics with the modular adapter is extremely fast: The white arrow on the Rusan ring that screws onto the Calonox eyepiece indicates where to insert it in correspondence with the white arrow on the Rusan tube mounted on the scope objective, then simply rotate the sliding locking ring less than a quarter turn in a bayonet lock on the eyepiece ring.
The further advantage of this adapter is that the ring (with the Calonox) has a fixed insertion position, which ensures the Calonox is positioned perfectly in line with the aiming line, avoiding further adjustments to get the reticle perfectly aligned with the Calonox screen.
Click here for the link to Rusan’s video on how the modular adapter works.
The Rusan modular adapter is imported by Forest Italia Srl and costs €255, VAT and shipping included (€180 for the standard one). It can be ordered directly here, or at the best gun shops. For information info@forestitalia.com – 045 8778772. When ordering, it is recommended to provide the model of the pointing scope to be associated with the Calonox Sight, or to indicate the external diameter of the scope objective based on the tables shown below.
The advantages of the modular adapter, in summary
- You can use the Calonox Sight (or Calonox 2 Sight) for observation with the Rusan ring mounted, to be ready to apply it quickly to the scope, enjoying the entire field of view perfectly. If you do the same with the Rusan one-piece adapter mounted on the Calonox, the thickness of the adapter tube makes observation less convenient.
- The transition from observation to aiming with the Calonox Sight is extremely fast. Simply insert the Calonox with the Rusan ring in the correct position (indicated by the white arrows on the ring and the other part of the adapter mounted on the scope) and rotate the locking ring less than a quarter turn. Two seconds.
- The Calonox attaches already perfectly aligned with the scope. This is the least intuitive but most important advantage compared to using the one-piece adapter. With the latter, you must ensure that the Calonox is centered relative to the scope’s aiming line, otherwise the scope’s reticle will appear rotated to the right or left. The fixed insertion position of the ring on the rest of the adapter allows you to perfectly center the part to be fixed on the scope before exiting, and thus be certain that when you go to insert the Calonox it will be immediately perfectly centered. Another important time saving, especially at night.
Given the quality of materials, design and workmanship, the centering retention of the modular adapter against recoil and assembly/disassembly operations is guaranteed.
On the other hand, the modular adapter costs €255 compared to €180 for the one-piece version, and for pure observation, the Leica rubber eyecup is certainly more comfortable and pleasant.
Here is a video tutorial on how to mount the modular adapter.
The Rusan 2.5x eyepiece for best observation, with diopter adjustment included
Rusan has produced a small (6cm by 90g) high-quality eyepiece with diopter adjustment and 2.5x magnification that attaches via bayonet to the ring part of the Rusan modular adapter and transforms the Calonox Sight and Calonox Sight SE, or the new Calonox 2 Sight and Calonox 2 Sight LRF, into an observation viewer truly at the same level as pure observation viewers. Here you will find all the details.
