EoTech XPS2-Z Zombie Stopper Holographic Weapon Sight Mounted Magnifier Dark Green Finish
http://www.amazon.com/gp/product/B007FX4XYO?tag=sukses2015-20
Shortest sight from EoTech to date
Provides up to 600-hours of battery life
Compact size allows for mounting of additional accessories
Parallax free optics