MS150 Non-Linear Spring

Details
Spring force: 15.63 kg Weight: 20 g Shipping weight: 40 g

Prometheus
Prometheus - a Japan-based company that can be easily described as "legendary" among new airsoft players and veterans alike. Best known for their superb inner barrels, Prometheus decided to expand further, providing top-notch tuning parts for gearboxes and hop-up units.