NBU set for AK series
Full NBU air system for power increase. Include chromium-plated cylinder, polycarbonate back pressure piston head with the bearing, stainless cylinder head with double O-rings and acetal nozzle with O-ring.
What is NBU? : NBU parts have increased inner diameter to hold more air capacity. It is ussually cylinder, piston head, cylinder head and nozzle. Typically sold as a complete set. It is recommended use M120 springs or higher to reach proper effect.
|Material||S303 Stainless Steel/Brass/Polycarbonate/Acetal|
|Purpose||Durability,better sealing, power increase|