Poseidon x CSI Theseus PDW M4 AEG – Medusa ETU, Integrated Tracer, Compact CQB Beast

The Poseidon x CSI Theseus PDW is not your average entry-level AEG. This compact rifle combines high-tech innovation with practical battlefield performance, delivering unbeatable value in a lightweight PDW platform. Built around the Medusa Electronic Trigger Unit (ETU) and a built-in tracer, the Theseus is tuned for domination — indoors or out.

With Bluetooth connectivity and app-controlled firing modes, the Medusa ETU puts full customization at your fingertips. Whether you're clearing rooms at a local CQB arena or skirmishing in low light, the quick-toggle integrated tracer and Poseidon's patented air cushion barrel help you land your shots with precision and style.

Designed with real players in mind, the Theseus PDW features a quick-change spring system, upgraded internals, and ambidextrous controls — all wrapped in a rugged yet featherweight polymer chassis. It's a serious tool for serious players, and it’s only available through Airsoft Extreme.

Key Features

• Bluetooth-enabled Medusa ETU – App-programmable fire modes, diagnostics, and updates
• Built-in Medusa Eye Tracer Unit – Toggle via trigger pull, supports red and green tracers
• Air Cushion Barrel System – Patented Poseidon design for tight groupings and increased range
• 8mm Bearing V2 Gearbox – Includes silent piston, full steel rack, QD spring guide, and MOSFET
• Lightweight PDW Platform – Polymer M-LOK handguard and receiver for fast handling
• Ambidextrous Controls – Fire selector and mag release accessible from both sides
• Oversized Battery Compartment – PDW stock fits 11.1V LiPo with ease
• Included 220rd Mid-Cap Magazine – No winding, no rattle

Product Demo Videos

Specifications

Length: 25 inch (retracted) – 28.7 inch (extended)
Weight: 5.3 lbs
Material: Reinforced polymer body, metal gearbox and internals
Barrel: 9 inch outer / 245mm inner
Magazine: 220rd mid-cap (included)
Gearbox: V2, MOSFET-equipped, Medusa ETU
Muzzle Velocity: 350–380 FPS w/ 0.20g BBs
Battery: 11.1V LiPo (not included)
Fire Modes: Safe / Semi / Auto / Burst (app-programmable)

Frequently Asked Questions

How do I activate the built-in tracer unit on the Theseus PDW?

The integrated Medusa Eye tracer is built into the hop-up unit and can be toggled directly via the trigger — no switches or external modules required. With Safe selected, just quickly pull the trigger three times to activate or deactivate. It supports both red and green tracer BBs.

What firing modes are available, and how do I switch between them?

The Theseus PDW includes three firing mode presets that can be toggled without the app. Simply set the selector to SAFE and hold the trigger for 3 seconds to cycle through modes:

• 1 pulse: Safe / Semi / Full-Auto
• 2 pulses: Safe / Semi / Burst
• 3 pulses: Safe / Binary / Burst

You can also fully customize these modes using the Medusa App via Bluetooth, including fire rate, burst count, and trigger sensitivity.

What type of battery does the Theseus PDW use?

The PDW-style stock features an oversized compartment designed for 11.1V LiPo stock tube batteries. This ensures excellent trigger response and performance without cramped wiring.

Is this airsoft rifle suitable for indoor CQB fields?

Yes. The compact footprint, lightweight polymer build, and integrated tracer unit make the Theseus PDW ideal for CQB. Its quick-change spring system also makes it easy to adjust muzzle velocity to meet indoor FPS limits.