The ELF APEX PRO Trigger has been built for performance. The ELF APEX PRO is identical to the APEX Trigger with the addition of a proprietary threaded mounting system. The combination of aerospace grade sealed bearings, precision ground threaded bushings, and screws instead of traditional pins provide a rock-solid trigger system. Since their inception, AR platforms have always used pins to mount the trigger and hammer in the lower receiver. Because pins require some play in order to be installed, there is always a little play in the trigger system. This new threaded system adds a level of solid you need to feel to understand the difference. Pull weight is so easy to adjust it can be done in seconds without removing the trigger from your lower receiver. A second-to-none AR- 15 drop-in trigger system that is strong and light, made of wire EDM machined, hardened A2 tool steel and lightweight aircraft-grade aluminum. Installation can be done in minutes using the supplied installation screws. The APEX PRO trigger may be ordered with a curved or straight shoe along in black or red. The amazingly short take-up, glass-rod crisp break, no skip technology and their new adjustable sear lets you customize the amount of creep you prefer in the trigger makes the ELF APEX PRO superior to others. Adjustability puts you in charge based on your current use. If you are looking for the finest adjustable trigger for your AR Platform, this is the trigger system for you.Features :Fits any and all AR platformsIncremental Adjustment KnobDrop-SafeAdjustable from 2 3/4lbs to 7lbs without removing from lowerPatented Double-Double torsion hammer springAdjustable sear to adjust the amount of creepNo Skip technologyMade of lightweight aircraft-grade aluminum & hardened steelAdjustable aluminum trigger shoe