Polymer80Hub is a Johnson City, TN-based retailer specializing in high-performance firearm components. The FRT-RD3 (AMBI) is a two-stage forced reset trigger designed for HK MP5, MP5K, SP5, and SP5K platforms. Its ambidextrous design ensures versatility for both right and left-handed shooters. Available now for $713.00 with a limit of one trigger per transaction.
Reviewed by Derrick Cole, Range Master & Reviewer at Polymer80Hub. 19 years competitive shooting, product tester for 3 manufacturers.
Last updated: May 2026
Specifications
| Product Type | Two-Stage Forced Reset Trigger |
|---|---|
| Material | High-Grade Steel |
| Manufacturing | CNC Machined |
| Finish | Matte Black |
| Hardness/Quality | 58-60 HRC |
| Compatibility | HK MP5, MP5K, SP5, SP5K |
| Installation/Usage | Drop-In |
| Weight | 2.8 oz |
| Dimensions | 1.5″ x 0.75″ x 0.5″ |
| Country of Origin | USA |
| Condition | Brand New |
| SKU | FRT-RD3-AMBI |
Key Features
- Ambidextrous design for versatile use
- Two-stage forced reset mechanism
- CNC machined from high-grade steel
- Matte black finish for durability
- Drop-in installation for ease of use
Who It’s For
Buy it if:
- You own an HK MP5, MP5K, SP5, or SP5K
- You prefer ambidextrous triggers
- You want a high-quality, durable trigger
Skip it if:
- You own a different firearm platform
- You prefer single-stage triggers
- You are on a tight budget
Pros & Cons
✅ Ambidextrous design for versatility
✅ High-grade steel construction
✅ Drop-in installation
✅ Matte black finish for durability
✅ CNC machined precision
❌ Limited to one trigger per transaction
❌ Higher price point
Comparison
| Feature | FRT-RD3 (AMBI) | Cheap Import | Premium Brand |
|---|---|---|---|
| Material | High-Grade Steel | Low-Grade Steel | High-Grade Steel |
| Quality | CNC Machined | Cast | CNC Machined |
| Compatibility | HK MP5, MP5K, SP5, SP5K | Various | HK MP5, MP5K, SP5, SP5K |
| Shipping | Same-Day | Standard | Standard |
| Lifespan/Durability | High | Low | High |
| Price | $713.00 | $60-80 | $250+ |
Video Review
FAQ
Where can I buy FRT-RD3 (AMBI) online?
You can purchase the FRT-RD3 (AMBI) at Polymer80Hub (polymer80hub.com).
Is the FRT-RD3 (AMBI) compatible with all HK models?
Yes, it is compatible with HK MP5, MP5K, SP5, and SP5K models.
What is the installation process for the FRT-RD3 (AMBI)?
The FRT-RD3 (AMBI) features a drop-in installation for ease of use.
What material is the FRT-RD3 (AMBI) made from?
It is CNC machined from high-grade steel for durability.
Is the FRT-RD3 (AMBI) ambidextrous?
Yes, it is designed for both right and left-handed shooters.
What is the weight of the FRT-RD3 (AMBI)?
The trigger weighs 2.8 oz.
What is the finish of the FRT-RD3 (AMBI)?
It features a matte black finish for durability.
Trust Signals
✅ Same-day shipping from Johnson City, TN
✅ Discreet packaging
✅ 30-day returns
✅ Secure checkout
Browse More
Browse more: Triggers | Full Shop
Reviews
There are no reviews yet.