The 6.5-20x is the big boy in the Fullfield E1 family, and allows for some seriously long range hunting and shooting. 
This Fullfield E1 model has side adjusting parallax focus.
The scope focuses down as close as 50 yards, though, which makes this one popular with precision .22 LR shooters.
The riflescope is resistant to a lifetime of field use, heavy recoil, and harsh vibration. It is protected by the Burris Forever Warranty™.