Heyco® Knock-Out Seals Features Plugs electrical knock-outs. Molded in gray color to resemble galvanized steel. Multiple trade sizes fit 1/2˝ to 2˝ knock-out holes. Locks firmly in boxes up to 1/8˝ thick, except for KOS2 and KOSTs which lock firmly in boxes up to 1/4˝ thick. Installs quickly with fingertip pressure (no tool required). Economical. Material 6/6 Nylon Certifications Recognized under the Component Program of Underwriters’ Laboratories File E51579 Certified by the Canadian Standards Association File LR8919 Flammability 94V-2 Temperature 257°F (125°C)–Maximum temperature on part not to exceed 221°F (105°C)

Heyco® Knock-Out Seals Specifications PANEL DIMENSIONS TRADE SIZE PART NO. DESCRIPTION PART DIMENSIONS CAD Maximum Thickness Mounting Hole Diameter Silver Gray A Head Diameter B Overall Height in. mm. in. mm. in. mm. in. mm. .125 3,2 .875 22,2 1/2 3997 KOS 1/2 1.015 25,8 .453 11,5 .125 3,2 1.093 27,8 3/4 3998 KOS 3/4 1.218 31,0 .453 11,5 .125 3,2 1.375 34,9 1 3999 KOS 1 1.500 38,1 .453 11,5 .125 3,2 1.750 44,5 1-1/4 4000 KOS 1-1/4 1.906 48,4 .453 11,5 .125 3,2 2.000 50,8 1-1/2 4001 KOS 1-1/2 2.140 54,4 .453 11,5 .250 6,4 2.500 63,5 2 4002 KOS 2 2.730 69,3 .750 19,1 Standard color silver gray. Locking fingers in fractional increments up to the maximum panel thickness. Approximate Head Thickness: .063˝ (1,6 mm). Thickness may vary.