Heavy duty because of weighted base. Not easily tipped. 

My experience with the screws for the "branches" was similar to other buyers. Here's what worked for me: screw them by hand as far as they would go ( not far). Push--hard-- a Phillips head screwdriver into the screw at the exact angle as the screw itself ( in other words straight on) and push while turning 

IMPORTANT: While turning the screwdriver it must remain  at the same angle as the screw AND you must keep pushing on the screw.

After about 3 turns the screws went in easily.