This is a used Benjamin Nitro Piston break barrel air rifle. This thing is powerful. Pretty much the most powerful non-pcp air rifle on the market. Gets about 900FPS with a 14.3 grain .22 pellet.
Works fine, shoots great, very accurate. Just downsizing my collection and I've replaced it with a very similar but lower power model that's a bit easier to cock.
The nitro piston system is like a springer, but it's much smoother shooting, less vibration.
Asking $200, will throw in 500 pellets as well.