This is in excellent condition, used but I suppose pretty close to as new, with the original box and all the bits. As far as I can see, couple of use/storage marks, as you would expect. Works as it should, very clear glass and sharp reticle.

Bought recently for a specific build, but I got the chance of something different and it came with a vortex optic, which I prefer

Pretty reasonable price at £145 plus post/fees 

see manufacturers blurb below and if you want all the details have a look at the retail link -

https://www.tactical-kit.co.uk/holosun-he403b-gr-dot-sight----green-reticle-35449-p.asp

The HE403B-GR is a 20mm micro optical sight designed for rifle and carbine applications. Features include 12 brightness settings, Holosun’s Green Super LED with up to 50k hours battery life, and 2 MOA Dot.

This ELITE micro reflex sight with green reticle offers an intelligent Shake Awake™ technology, a long operating life, a high riser mount, and a durable alumin housing at small weight.

With our reflex sights you get a military-grade quality at an unbeatable price-performance ratio - without any compromises. They allow to focus your target with both eyes open. Thanks to this the sights are ideal for hunters, sports marksmen, authorities, and airsofter. Besides the multi reticle system (500 line) and the solar models (C-line) all optics offer an intelligent Shake Awake™ technology for an extraordinary long operating life, a parallax-free performance, a bevelled front lens (micros, tubes) and 12 brightness levels for manual brightness control. Our sights can also easily be combined with aiming lasers and night vision devices.

• Perfect for hunting, sport shooting and airsoft.
• 2MOA green dot with 12 brightness settings and side battery compartment with 2 screws.
• Long service life: ultra-efficient green LED Technology, Shake Awake function and automatic Brightness control allow up to 50,000 operating hours.
• Premium sights of military standard to an unbeatable value for money.
• Always ready for use: with state-of-the-art technology, Shock-proof construction and resistant coating designed for the toughest conditions.