This standard covers composite guy (strain) type insulators made of a fiberglass-reinforced resin matrix core, an ultra-violet light-resistant polymer material rod cover, and metal end fittings intended for use on overhead lines for electric power systems to insulate or isolate guy wires for corrosion protection, increased insulation levels, or clearance for maintenance and normal operation. Strain type insulators with other ultra-violet light-resistant coatings such as painted or veiled fiberglass-reinforced core rods are covered in NEMA Standard C29.14B.