Easy enough to assemble. Estimated time according to the instructions was an hour, which was about right. The heaters were used for a birthday party during a rainstorm In November with temps dropping to about 38°. They held up fairly well, produced enough warmth for everyone sitting close. They don’t radiate outward a whole lot and truly, that was why I gave it 4 stars. We’ll see if they can hold up for more than just a couple of uses, though.