The TruBall ST-3 and ST-4 are the new tournament versions of our incredibly popular Sabretooth release. We've added the Boss/Xtreme cocking mechanism for a non-moving, crisp trigger and a new 1 oz. to 9lbs. Spring Change System. The competition uses a trigger with .009 (nine thousandths) movement, much like our Sabretooth. We have developed a trigger with no more than .001 (one thousandths) movement, a third the size of a human hair! Test it out and see for yourself how this release can increase your X's!