One post, cap and sleeve 10 ft finished height (3 parts to make one completed support post 10 feet above the ground).
This post has a removable or permanent extension set in place with a self tapping screw.
The sleeve includes a locking set screw. The sleeve goes into the ground, the cap on the post then the post slides inside the sleeve - the set screw holds the post inside the sleeve (patent pending).
These 10 foot finished height single post, cap & sleeve assemblies are available for purchase in quantities of 5 or more.