KAC-Knight's Armament SR-25 Ejection Port Cover Assembly, Extended-LIMIT 2
Knight's Armament
$38.31
KAC-Knight's Armament SR-25 Ejection Port Cover Assembly, Extended-LIMIT 2 (25934)
Other parts required for a complete assembly:
https://www.operationparts.com/kac-knights-armament-sr-25-ejection-port-cover-pin-limit-2/
https://www.operationparts.com/kac-knights-armament-sr-25-ejection-port-cover-spring-limit-2/