Radiata Inc. Fretensis Foundation – MP5K / SP5K Fixed Magazine Drop-In Solution

The Fretensis Foundation by Radiata Inc. is a complete drop in fixed-magazine trigger housing for compact MP5K and SP5K clones. Designed to be an added magazine retention device that will not allow the magazine to be accessed while the trigger mechanism is connected to the firearm.

One press of the discreet button ergonomically disconnects the trigger housing.

Fretensis Tier Comparison All models feature the patent-pending redundant locking system and polymer + steel hybrid construction.

• Foundation – 3.5 lb flat-faced NiBo single-stage trigger + buffer.
• Performance – Radiata 2-stage battle trigger (4 lb total) + Blackout Defense 45° ambi safeties + buffer.
• Apex – Geissele SSA-E trigger (2.9–3.8 lb) + FCD Q-50 safety with custom levers + buffer.

Important Compliance & Legal Information Buyer is solely responsible for understanding and complying with all federal, state, and local laws. Laws change — always verify with your states DOJ or a qualified attorney. This is not legal advice. For lawful use only.