Sprenger: Stainless steel spring designed for 8mm pulleys in synthetic material - - Stainless steel spring designed for 8mm pulleys in synthetic material, conical shape, 24/29mm interior, low weight of 10 grams. Suitable for: - 420 - 445 - 470 - 485 - 490 - 505 - Cadet - Contender - Europe - Flying Dutchman - Finn - Fireball - Koralle - Korsar - Laser - Lightning - Marauder - Moth - Open 5.00 - Open 5.70 - Optimist - Pirat - Ponant - Topper - Vaurien - Windy Spring