The strength of a forged aluminum alloy. The lightness of a hollow axle. The ultra-low, no-hangup profile of an inverted kingpin. The rep of riding Indys. These trucks have it all.The Indy Mids feature a lower profile hanger for optimal contact point angle on your nose and tail for flip tricks, ledges, and all-around street skating. The inverted kingpin works with a 5.5mm Allen key or standard 9/16" hex wrench, and sits low so you can dip those smith grinds with ease.The innovative Shaft Nut in the baseplate creates a rigid and durable solution to lateral movement found in most inverted kingpin designs and increases adjustability.Basically, Indy done did it again. 356 Aluminum hanger and baseplate 4140 Chromoly steel axle 50.5mm tall for optimal performance Inverted Grade 8 kingpin Steel Shaft Nut with nylon locking insert Patent Pending 139s are for decks approx 7.75" - 8.25" wide