4'' gong, made from AR500 1/2 (.500) thick (AR500 steel is an abrasion resistant steel plate used in body armor and ballistic plates. This steel is heat treated to exhibit through-hardening. With a typical BHN (Brinell Harness Number) of 460 – 544, the protection AR500 provides it can withstand high impact stresses, even at extremely low temperatures). All of our products are CNC Fiber Laser Cut for a practically non-existent HAZ (Heat Affected Zone). This Gong is made with two 1/2" holes for easy setup for your targeting. Also available in 1/4'' and 3/8'' thick versions. Don't forget to order your hardware kit for turnkey setup.