AC, HP, Stamina, and Agility. You could even argue Mana for heals. The negative Strength and the +10 Fire Resist.. only the -10 Cold Resist keeps these from looking 100% like they were meant for tanking.
I remember seeing, on Rallos Zek, Serpentine Bracers constantly going for 2pp-ish, even in the earlier years. Agility's a great melee mitigation stat that seems to be overlooked quite a bit in favor of pure AC. Just helps me smile, every time I see something with some nice Agility on it for a tank.