These thick platinum armbands are etched with a pattern of crossed hammers.

Bracers of great collision allow you to deliver particularly crushing attacks with bludgeoning weapons. When you score a successful critical hit with a bludgeoning melee weapon, you can activate the bracers to deal an extra 2d6 points of damage with that attack (or 3d6 points of damage if you wield the weapon with two hands).
You must activate the bracers before you roll damage for the critical hit.
Bracers of great collision function two times per day.

Prerequisites: Craft Wondrous Item, greater magic weapon, keen edge.
Cost to Create: 500 gp (plus 500 gp for base item), 40 XP, 1 day.