Brass catcher for upper receivers with charging handles on ejection port side.
Caldwell AR15 Pic Rail Brass Catcher -The Firearm Blog
Brass catcher for side charger upper receivers
BCA trash or treasure? I tried out the side charging 20 .223 Wylde so you don't have to. my review in the comments: : r/ar15
Tactical Brass Recovery™ Operator MID Length Brass Catcher AR-15 / AR-10 - MULTICAM BLACK - 4GT.com
Brass catcher for side charger upper receivers
AR 15 & Gun Accessories, AR 15 Attachments, Tactical Brass Catcher – Magwell Mounts
Tactical Brass Recovery™ Operator LONG Length Brass Catcher AR-15 / AR-10 - BLACK - 4GT.com
Brass catcher for side charger upper receivers
Brass Catcher for AK by Custom Cast Usa - Canada