Looks like they are catching up with times on the head and trying to have a easy get, in the 800 market! 
The tail kit to make your 700 a 800 H80001 800 Stretch Kit Upgrade Tail Assembly
And the newly design adjustable head HN7114 700 New Designed Main Rotor Head Assembly

The tail kit to make your 700 a 800 H80001 800 Stretch Kit Upgrade Tail Assembly
And the newly design adjustable head HN7114 700 New Designed Main Rotor Head Assembly







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