The MEC Centra Duplex Vario (3.4 – 4.4) is an adjustable rearsight extension tool used in competitive ISSF target rifle shooting (10m air rifle, 50m smallbore, and 300m fullbore). It mounts between your rearsight iris and front sight tunnel to provide a second internal ring—giving immediate visual feedback on head alignment and centering consistency.

Key Technical Specifications

1. Aperture Adjustment Range: 3.4 mm to 4.4 mm continuous variable inner ring diameter.
2. 
   
3. Compatibility: Specially sized for setups with short sight radii or short anti-glare tubes (such as the Centra SPY rearsight or compact rearsight extensions).
4. 
   
5. Positioning Control: Built-in horizontal (X) and vertical (Y) micro-adjustment screws to align the inner ring precisely to your individual sight line.
6. 
   
7. Modular Interface: Features integrated threading to attach optional accessories like a Duplex Iris or color filter lorgnettes.
8. 
   

Core Benefits for Target Shooters

1. Head Alignment Indicator: By introducing an intermediate ring into your sight line, any slight canting or improper cheek-weld alignment immediately causes uneven ring margins around the front sight tunnel.
2. 
   
3. Reduced Eye Strain: Allows you to adjust the visual gap between your rearsight iris, front sight tunnel, and the target black, making focus acquisition smoother during long match strings.
4. 
   
5. Tool-Free Adjustability: The outer knurled adjustment ring lets you adjust the inner ring diameter instantly on the firing line to compensate for changes in light or target distance.