Зап. части DragonFly - Stingray "No. 78 - Inner piston spring Stingray STD (2261)"
The Inner piston spring controls the return action of the inner piston. Like all springs it will get weaker / softer with time, if the inner piston starts to clatter (sound ratteling) it can be a sign that it is to weak. To resolve this you can either replace it with a new or you can stretch it about 2mm. Also make sure that the inner piston is oiled and moves easy.