The Geissele G2S is a drop-in two-stage trigger for AR-15 and M4 pattern rifles, fitting Mil-Spec lower receivers that use .154 in trigger and hammer pins.
The Geissele G2S (05-145) exists to put a genuine Geissele two-stage into more rifles. The pull follows the SSA's profile — smooth first-stage take-up into a crisp, reliable second-stage break — manufactured with streamlined production rather than by cutting the metallurgy or the safety margin that make Geissele triggers trustworthy.
For a first trigger upgrade, the G2S is transformative: mushy, gritty factory pulls become a clean two-stage you can actually shoot to the rifle's potential. It drops into any Mil-Spec AR-15 lower and runs full-power ignition springs.
Key Features
- True Geissele two-stage pull — SSA character, the entry point to the Geissele line
- Crisp, repeatable break — an immediate upgrade over any factory trigger
- Full-power ignition springs — dependable primer strikes
- Drop-in Mil-Spec fit — standard .154 in pins
Compatibility & Fitment
The G2S is a drop-in fit for AR-15/M4 pattern lower receivers using Mil-Spec .154 in trigger and hammer pins. It will not fit large-pin receivers — confirm your pin size before ordering. Installation is armorer-level work; carry out full function and safety checks after fitting and before live fire.
Technical Specifications
Platform | AR-15 / M4 |
Fits | Mil-Spec lower receivers with .154 in trigger and hammer pins |
Type | Two-stage trigger |
Made in | USA |
Brand | Geissele Automatics |
US Shipping & Support
Shipped from D&R Sports Center in the USA with fast, tracked delivery. Questions on fit, mounting or which model suits your setup? Our team is glad to help before and after your purchase.
Frequently Asked Questions
Which lowers is the G2S compatible with?
It is a drop-in two-stage for AR-15/M4 pattern lower receivers running mil-spec trigger pins. It will not fit large-pin receivers, so confirm the pin size before ordering. If you are not sure what your lower uses, send us the make and model and we'll advise.
Where does the G2S sit in the Geissele line-up?
The G2S is the accessible entry point to Geissele's two-stage triggers: the same basic two-stage feel of a take-up stage followed by a clean break, positioned below the Super family. It is a straightforward, non-adjustable unit with nothing to set up. If you have only ever used a standard mil-spec trigger, the difference is immediately obvious.
What do I give up compared with the SSA?
The SSA is the benchmark two-stage with a more refined break and finish, and the SSA-E lighter still; the G2S trades some of that polish for value. For most range and general-purpose use the G2S is plenty. If you shoot precision regularly, the step up is worth considering.
Do I need anything else, and is there a choice of version?
It is offered in one configuration and installs with your existing standard trigger and hammer pins, so no extra hardware is needed if they are in good condition. Always carry out a full function and safety check before live firing.
