Designed to meet those requirements wherein the Strain Relief device must remain attached to the panel during cable removal or replacement.

• Captive acetyl screw^†cannot be removed from body during cable removal or replacement. (The screw forces the locking flap against the cable.)
• Reinforcing ribs provide extra strength.
• Nylon USR-400 Series parts may help you comply with IEC Publication #335, CEE #10 and #11; VDE #0720, #0730, and others.
• Protects your cable against forces of pull, push, twist and flex.
• Prevents use of larger-than-intended cord diameters.
• Easy panel installation. Fingertip pressure locks bushing into .875" (22,2 mm) holes with panel thicknesses up to
  .125" (3,2 mm).
• No need for separate cord guard. The bushings' cord exit features a bell-mouth contour, with radius at 1-1/2 times the exit hole diameter.
• USR-40 uses captive metal screw and USR-400/401 uses a captive acetyl screw.
• Create Double D mounting holes with a Heyco Strain Relief Hole Punch.
• Fill blank/unused mounting holes with Heyco Double D Plugs.