The #40L has all the features of the excellent 40A2 sight, but has a lower profile, allowing more clearance for mounting optics to your flat-top receiver and allows lower mounting, miniaturized windage knob with .75 MOA adjustment and a very new and unique dual aperature. Folded height is only .610".

Features and Specifications:
Manufacturer Number: 40L
Miniaturized windage knob with .75 MOA adjustment
Allows more clearance for mounting optics
Allows lower mounting
Lower Profile
Dual aperature