This is a Pulsar Thermal Weapon Sight known as the Digex, model PL76641.
Full-featured Digital Night Vision Riflescope designed in the shape of a classic day sight. The form factor of the Digex includes the lowest possible mounting point" flexible location on the rifle due to standard 30mm tube size.
Features:
Over 500m Nighttime viewing range
Integrated video and sound recorder
HD-sensor
Easy mounting on a rifle
4x-16x Variable Magnification
Scalable ballistic reticles
Picture-in-Picture mode
Long-range IR Illuminator
Wi-Fi compatibility with iOS and Android devices
Recoil resistant up to 375 H&H, 12GA, 9.3x64