Next Level Armament Ascend Ambidextrous Safety Selector for AR-15 and AR-308

An ambidextrous safety selector puts a lever on both sides of the lower receiver. For a left handed shooter that puts the safety under the trigger finger instead of under the grip; for a right handed shooter it adds a lever the support hand thumb can reach.

Ascend lists this one for both AR-15 and AR-308 lower receivers, so the same part covers a 5.56 carbine and a large frame rifle. It goes in where the existing selector comes out.