These are high quality, beautifully finished carbon fiber main blades for your 500 size helicopter. The airfoil and weight balance of these blades has been optimized to give the best cyclic response and control for helicopter models with a traditional flybar head. Although the majority of these blades are perfectly finished, they are sold as B-grade finish blades which means there may be a bit of overspray or smudged paint lines. This in no way affects the quality/performance of these blades and most look perfect despite being sold as B-grade. You wont find a better price on main blades of this quality anywhere else! *Perfect for use with Trex 500/Lepton 500 helicopter and other 500 size helis. Specs: Length: 430mm (bolt hole to blade tip) Weight: 64g each Bolt hole: 3mm Grip: 9mm (includes 1mm shims to fit 10mm blade grips)