NcStar VISM AR-10 Upper Receiver Block VTHAR10UVB kbar providing correct eye relief and

providing correct eye relief and head placement when used on your rifle

No worries

1° Field Of View FT @1000 YARDS 319 ft Field Of View M @1000 METERS  117 m Close Focus  4 m /13 ft Interpupillary Distance 56 mm-76 mm Weight 25

Alleviates neck strain during long days in the field

but they render themselves useless when the task calls for a more versatile tool

NcStar VISM AR-10 Upper Receiver Block VTHAR10UVB kbar providing correct eye relief andBolting the two halves of the upper receiver block fully supports the upper receiver to prevent damage from torque twisting forces when installing or removing barrels from the receiver. The upper half of the block inserts into the AR10 receiver just like a bolt carrier group. The bottom half of the block can be bolted together with the upper block half with the provided steel bolts. This fully supports the inside and the bottom of the AR10 receiver