You can find the Timney Triggers Impact AR Trigger Curved here.

The Timney Triggers Impact AR Trigger is an affordable and easy to install drop in trigger for your AR-15. Timney's engineers found a way to machine the parts from billet steel, assemble the triggers, and still hand-test the trigger while keeping the price low. The single-stage trigger has a crisp, clean, 3-pound break.  Not compatible with AR-10 or 15-22.

Trigger Pull Weight: 3.0lb
Trigger Style: Single Stage Curved
Pins: Small Pin (Mil-Spec)