Equipped creature can block an additional creature each combat.
1/1/2011 Destroying or unequipping the Echo Circlet after blockers have been declared will not undo any blocks made by the equipped creature.
1/1/2011 Echo Circlet’s effect is cumulative. If it equips a creature that can already block an additional creature, now it can block three creatures. The same is true if two Echo Circlets equip the same creature, for example.