Red DMC L150 Type Support Busbar Insulator

L type" is not a standard type of electrical overhead line insulator (such as Pin, Disc, Shackle, Post, or Suspension). The term "LT" is commonly used in technical specifications to mean Low Tension (low voltage), which likely corresponds to what you are looking for. LT insulators are typically used for voltages up to 1.1 kV. The main types are Pin Insulators and Shackle Insulators (also known as Guy Strain Insulators )