The new Atom Smasher Trigger System (ASTS) with flip switch has a few upgrades.

-  Flip witch firing selector for better visibility
-  New hand grip with AG1 ASA attachment capability
-  Compatible with T-Series Marker: Gen1, Gen2, Gen3 Gen4 Gen6, Gen7.

Note:  If your marker has a post 2010 E-trigger, you need to change the Hammer Version, part #42-TMG4 and #41 Hammer Dampener.

- For grip options ( more info )