How does the thumbscrew clamp on the Outdoor Standing String Light Posts adjust to different surfaces?

The standing posts use a thumbscrew clamp that adjusts from 0.5" to 3.5" to attach to different surface thicknesses. The clamp depth adjusts from 0.5" to 3.5". The posts attach to the surface with the thumbscrew clamp.

What is included with the Outdoor Standing String Light Posts, and what is sold separately?

The standing posts include two posts and mounting hardware; the posts do not include string lights, and the horizontal bar is sold separately. The standing string light posts are a set of 2. Mounting hardware is included. String lights are sold separately. The horizontal bar is sold individually.

Are the Outdoor Standing String Light Posts intended for outdoor use, and can they be inserted into the ground?

Yes, these posts are outdoor safe, but this set is not intended for ground insertion. They are made for outdoor use. They are not intended for ground insertion.