Geissele G2S Two-Stage Trigger - AR-15
Mix and match across the range: 2 items save 5%, 3 save 10%, 4 or more save 15% on your whole basket.
Drop-in fit for AR-15/M4 pattern lower receivers with mil-spec trigger pins. Confirm pin size before ordering.
Not sure it fits your rifle? Ask us before you order
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.
Geissele's gateway two-stage trigger — the G2S delivers the house pull at the sharpest price in the line-up.
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 to reach a price point, not 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.
The G2S is a drop-in fit for AR-15/M4 pattern lower receivers using Mil-Spec .154 in trigger and hammer pins, so it suits a UK straight-pull AR-15 build as readily as any other AR-pattern lower. It will not fit large-pin receivers — confirm your pin size before ordering. Installation is armourer-level work; carry out full function and safety checks after fitting and before live fire.
| 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 |
| MPN | 05-145 |
Your first Geissele — and a proper one. Order the G2S today — imported from the USA with all duties paid by us and dispatched tracked from the UK in 7–10 business days, with nothing to pay on delivery.
Explore more: all Rifle Triggers, AR-15 Parts & Accessories or browse all Geissele Automatics.
| 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 |
| MPN | 05-145 |
| Category | Trigger |
| Shipping weight | 0.2 kg |
| Barcode | 854014005045 |
£5 tracked UK delivery on every order via Royal Mail Tracked 24. Our products are ordered in from the manufacturer rather than held in UK stock, so please allow 7 to 10 business days (Monday to Friday, excluding bank holidays) from the date of your order for it to reach you. Tracking details are emailed on dispatch. UK delivery only.
You have 30 days from receiving your order to cancel it for any reason, then 14 days to send it back unused and in its original packaging. Faulty, damaged or incorrect items are replaced or refunded and we cover reasonable return postage. Refunds go back to your original payment method within 14 days of receiving the return.
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.
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, at a noticeably lower price than 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.
The <a href="/products/geissele-ssa-trigger-ar-15">SSA</a> 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.
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. The rest of the <a href="/collections/geissele-automatics">Geissele Automatics</a> range is worth a look if you want to compare before buying.
This one ships from the United Kingdom with £5 tracked UK delivery in 7–10 business days and an email with tracking when it goes. If it turns out to be the wrong fit for your rifle, see our returns policy or <a href="/pages/contact">contact us</a> and we'll help sort it.
7 to 10 business days from the date of your order. Every order is sent Royal Mail Tracked for a flat £5 and you receive tracking details by email when it is dispatched.
Yes. We list only genuine parts and optics from the brands shown, ordered in from the manufacturer for your order.
Compatibility notes on this page come from the manufacturer. If you are unsure, email us with your make and model before ordering and we will check rather than guess.
Yes. Bundle & Save applies automatically in your basket: 5% off when you buy 2 items, 10% off at 3 items and 15% off at 4 or more. It works across the whole range, so you can mix and match, and there is no code to enter.
Yes — you have 30 days from delivery to cancel for any reason, as long as the item is unused and in its original packaging. See our returns policy for the details.
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