4 Wood blades (2 pairs) E-Flite Blade CP, CP+, CP PRO, CP PRO 2, OR BLADE SR. 246mm overall length. 2mm hole diameter fits Blade CP, SR, series helicopters without any slop . **** IMPORTANT: DO NOT USE WITH Blade 300 X. THESE DO NOT HAVE THE BRASS INSERT REQUIRED FOR THE HIGHER HEAD SPEEDS OF THE BLADE 300 X SERIES For the Blade CP Series through Blade CP Pro 2 and Blade SR:These will work for all types flying (sport aggressive 3d). These fit a bit snug at in the blade grips, but do work fine.