Polymeric suspension rod line insulators are designed for insulating and securing conductors of overhead power lines (OPL) and busbars of distribution devices of power plants and substations for alternating current with voltages ranging from 10 to 500 kV and frequencies up to 100 Hz. They are effective under various atmospheric pollution conditions. The climatic design of the insulators corresponds to category UHL, placement 1 according to GOST 15150, allowing operation at temperatures from -60°C to +50°C and at altitudes up to 1000 m above sea level.

The insulator's construction includes a fiberglass rod providing mechanical strength and a protective sheath made of silicone rubber, which shields the rod from atmospheric effects and increases the leakage path length. Metal end fittings ensure the connection of the insulator with conductors and OPL support elements. For OPL with voltages of 110–220 kV, insulators are equipped with grading rings to reduce radio interference levels and equalize voltage distribution along the insulator.

Insulators are classified by the following parameters:

• Design type: rod suspension line (L).
• Protective coating material: silicone rubber (K).
• Nominal voltage: from 10 to 500 kV.
• Mechanical breaking strength in tension: from 70 to 210 kN.
• Type of end fittings: clevis-tongue (SP), clevis-clevis (SS), socket-tongue (GP), socket-clevis (GS).
• Maximum pollution level: from 1 to 4 according to PUE, 7th edition, ch. 1.9, STO 56947007-29.240.068-2011.

Example of designation: LK 70/110-2SP, where:

• LK — line rod suspension polymer insulator with a protective sheath made of silicone rubber.
• 70 — mechanical breaking strength in tension in kN.
• 110 — nominal voltage in kV.
• 2 — pollution level.
• SP — type of end fittings: clevis-tongue.

Insulators are produced in various modifications: SP, SS, GP, GS, with connection dimensions corresponding to standards for 7-ton, 12-ton, 16-ton, and 21-ton series.