The S3G was developed to combine the SSF combat trigger's match-grade semi-automatic performance with its smooth single-stage full-automatic feel to make a fast, smooth, and robust trigger ideal for 3 Gun competition shooting. Features: Type: Single Stage 1st Stage Weight: 4.0lbs 2nd Stage Weight: N/A Total Pull Weight: 4.0lbs (3.25lbs or 4lbs depending on spring Adjustable: No Size: Mil-Spec Trigger Bow Type: Flat Weapon Platform: AR15/AR10 Note: The SD3G trigger has a very short, light pull and reset. We do not recommend it for duty use, bench rest, accuracy work or shooting small groups. It is designed for close course competition use where rapid target engagement with quick follow up shots are required.