The Colt Sporter Cheekpiece was designed to provide elevation of stock cheek weld when using carry handle mounted optics on Colt AR-15 rifles. These cheekpieces came as factory installed accessories on the R6600DH Delta Elite, R6601DH Sporter Match Delta Elite and the R6700CH Sporter Competition HBAR rifles. They are compatible with standard fixed buttstocks only.
When the Colt Sporter Cheekpiece is installed, it raises the stock comb height about 1.25 inches to better align the shooters eye with the installed optic.
The example shown in the photos was sold on Gunbroker.com 27 OCT 2019 for $195.00.
There was a similar cheekpiece marketed by Cherokee Accessories.