Independent 109s feature a retro, Stage 1 inspired T-hanger design that is great for small skateboards 6.25 to 7.5 inches.55mm tall for optimal performance and wheel clearance with wheels 56mm and under.A356 T6 Aluminum Hanger & BaseplateThe best lightweight aluminum alloy heat treated to T6 condition for strength, durability, and grind feel.SCM435 Chromoly Steel AxleHighest quality and durability available.Grade 8 KingpinNever break, never bend.Super High Rebound 90a Cushions109s feature 6 hole universal baseplate with old and new school mounting pattern.Independent Trucks are Built to Grind and Guaranteed for Life.