This shield is designed for throwing and has specially designed straps allowing you to unclasp and throw it as a free action. Tower shields cannot be throwing shields.
Neither a shield’s enhancement bonus to AC nor its shield spikes apply on your attack or damage rolls.
Added in Ultimate Equipment: A throwing shield can’t be disarmed.
Pathfinder Roleplaying Game Ultimate Combat. © 2011, Paizo Publishing, LLC; Authors: Jason Bulmahn, Tim Hitchcock, Colin McComb, Rob McCreary, Jason Nelson, Stephen Radney-MacFarland, Sean K Reynolds, Owen K.C. Stephens, and Russ Taylor.
Pathfinder Roleplaying Game: Ultimate Equipment (OGL) © 2012, Paizo Publishing, LLC; Authors: Dennis Baker, Jesse Benner, Benjamin Bruck, Ross Byers, Brian J. Cortijo, Ryan Costello, Mike Ferguson, Matt Goetz, Jim Groves, Tracy Hurley, Matt James, Jonathan H. Keith, Michael Kenway, Hal MacLean, Jason Nelson, Tork Shaw, Owen KC Stephens, Russ Taylor, and numerous RPG Superstar contributors