Tetragunshop is a Memphis, TN-based retailer specializing in firearms and accessories. The FRT-RD3 (SEF) is a two-stage, three-position forced reset trigger designed for HK MP5, MP5K, SP5, and SP5K models. This trigger offers enhanced performance and reliability. Available now for $707.25, with a limit of one trigger per transaction.
Reviewed by Marcus Tate, Owner & FFL Holder at Tetragunshop. Tennessee-licensed FFL dealer since 2014, USPSA Production-class competitor.
Last updated: May 2026
| Product Type | Forced Reset Trigger |
|---|---|
| Material | High-grade steel |
| Manufacturing | Precision CNC machining |
| Finish | Hardcoat anodized |
| Hardness/Quality | Durability tested |
| Compatibility | HK MP5, MP5K, SP5, SP5K |
| Installation/Usage | Professional installation recommended |
| Weight | 3.2 oz |
| Dimensions | 2.5 x 1.2 x 0.8 inches |
| Country of Origin | USA |
| Condition | New |
| SKU | FRT-RD3-SEF |
Key Features
- Two-stage, three-position design
- Enhanced trigger reset for faster follow-up shots
- Compatible with HK MP5, MP5K, SP5, and SP5K
- Precision CNC machining for consistent performance
- Hardcoat anodized finish for durability
Who It’s For
Buy it if: You own an HK MP5, MP5K, SP5, or SP5K and want to improve your trigger performance for competitive shooting or home defense.
Skip it if: You’re looking for a budget-friendly option or don’t own a compatible firearm. Check out our Triggers category for alternatives.
Pros & Cons
- ✅ Enhanced trigger reset for faster follow-up shots
- ✅ Precision CNC machining ensures consistent performance
- ✅ Hardcoat anodized finish increases durability
- ✅ Compatible with HK MP5, MP5K, SP5, and SP5K
- ✅ Made in the USA
- ❌ Higher price point compared to some alternatives
- ❌ Professional installation recommended
Comparison
| Feature | FRT-RD3 (SEF) | Cheap Import | Premium Brand |
|---|---|---|---|
| Material | High-grade steel | Aluminum | Stainless steel |
| Quality | Durability tested | Variable | High |
| Compatibility | HK MP5, MP5K, SP5, SP5K | Limited | Broad |
| Shipping | Same-day | Standard | Standard |
| Lifespan/Durability | Long | Short | Long |
| Price | $707.25 | $60-80 | $250+ |
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FAQ
Where can I buy FRT-RD3 (SEF) online?
You can purchase the FRT-RD3 (SEF) at Tetragunshop (tetragunshop.com).
What does SEF stand for?
SEF stands for Safe, Semi-Auto, Full-Auto, indicating the three positions of the trigger.
Is the FRT-RD3 (SEF) compatible with other firearms?
No, it is specifically designed for HK MP5, MP5K, SP5, and SP5K models.
What is the penalty for non-compliance of FEMA regulations?
Non-compliance can result in fines or other legal penalties, depending on the specific regulation violated.
Is professional installation required?
While not mandatory, professional installation is recommended to ensure optimal performance.
What is the return policy?
We offer a 30-day return policy for unused items in their original packaging.
Is the trigger shipped discreetly?
Yes, all orders are shipped in discreet packaging for your privacy.
Trust Signals
✅ Same-day shipping from Memphis, TN
✅ Discreet packaging
✅ 30-day returns
✅ Secure checkout
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