BCM Charging handle.
Bravo Company USA, Inc. AR-15, M16, M4 Tactical Gear, Parts, Accessories.
I got the MOD 3 (large) version, much easier to use.
I've heard people say if you carry the AR with a BCM handle strapped to your chest (2point sling), that the handle can dig in your chest, but I hadn't noticed the issue when I tried mine with a sling.
FYI, I have the MissionSpec- Irene Adaptive Sling (IAS), it's sweet.
It's a 2-point, and single-point sling
JoeBobOutfitters.com - IAS Sling