The LKP 120/20-I (IG) type polymer suspension line insulators with bird protection are designed for securing and insulating bare conductors of overhead power transmission lines (PTL) operating at 10–35 kV AC with frequencies up to 100 Hz. They provide protection for birds against electric shock upon contact with the insulator and prevent PTL outages caused by electrical flashovers due to birds or contaminants flowing from the crossarm of the support. The use of these insulators eliminates the need for additional bird protection devices. They are suitable for operation in ambient temperatures ranging from -60 °C to +50 °C and comply with the climatic version and placement category UHL 1 according to GOST 15150. Manufactured in accordance with TU 3494-005-57966314-2006, these insulators meet the standards of GOST 28856, GOST R 55189, and IEC 61109.

Key technical specifications of the LKP 120/20-I (IG) insulators include:

• Rated voltage: 20 kV.
• Rated mechanical breaking load: 120 kN.
• Overall height: from 430 to 505 mm, depending on the model.
• Insulation height: from 285 to 360 mm.
• Leakage distance: from 710 to 880 mm.
• Withstand voltage of full lightning impulse: from 215 to 275 kV.
• Power frequency withstand voltage in dry conditions: from 105 to 130 kV.
• Power frequency withstand voltage under rain: from 65 to 110 kV.
• Power frequency flashover voltage in polluted and wet conditions: not less than 26 kV.
• Specific surface conductivity of pollution layer: from 10 to 50 μS/cm.
• Permissible pollution degree according to GOST 9920: from II to IV.

The insulators are available with various combinations of end fittings, including: "fork-tongue" (VP), "fork-clevis" (VC), "socket-fork" (GV), "oval-clevis" (OS), "oval-tongue" (OP), "socket-oval" (GO), "clevis-tongue" (SP), "clevis-clevis" (SS), "socket-tongue" (GP), and "socket-clevis" (GS).