Troy engineered a rugged, reliable, BattleReady™ BattleSight™ that mounts securely on the gas block. It offers all of the features of Troy’s other Folding BattleSights: Easy to operate, clicks solidly into place, and folds out of the way when not needed. Not compatible with four-sided rail gas blocks.
Mounts securely on the gas block.
Built-in swivel attachment on both sides.
Designed to work on gas blocks that are lower than the upper receiver plane.
Note: Does have minor marks and dings.