Progressive AEG spring - SP150
Oil Quenched/Tempered Si-Cr Alloy Steel Wire. Not for TokyoMarui PSG-1. Progressive (nonlinear) winding gives lower resist at the first phase of pressing, but spring keep the same power.
is a world-famous brand of the Taiwanese Intruder Shop, which was introduced in 1997. The Intruder Shop itself was founded even earlier, in 1994 as a provider of police equipment to the local market. However at the turn of the millennium, it focuses mainly on airsoft and becomes one of the most famous brands in airsoft. Guarder offers a wide range of parts and accessories for airsoft weapons - from springs, cylinders, pistons, through mounts and gun accessories, to BBs. Guarder is also known for its quality upgrade parts for airsoft replicas.