Compatable with Uh45 / 55 / 5580 / 6576570 / 6580 / Uc4020A / 3520A

The Makita part number 158024-1 is a hook for an extension cord, also referred to as a cable retaining hook or traction relief. 
Its primary function is to secure a power cord to an extension cord, which prevents the cords from accidentally disconnecting during tool use. 
This spare part is compatible with several corded Makita tools, including various chainsaws and hedge trimmer models such as the HK1820, UC4051A, and specific models in the UH series (e.g., UH4570, UH5580, UH6580)

Please see below for all applicable models: