The Firearm Blog: San Tan Tactical STT-15 Lower

San Tan Tactical is making an AR-15 lower that was designed to be completely ambidextrous, including the magazine release and the bolt release.  Additionally, the lower has integrated QD sling attachment points on both sides.

https://www.thefirearmblog.com/blog/2013/10/08/san-tan-tactical-stt-15/