How many letters does the top answer for “optical device that helps a user to find the target of interest” have?

The most common answer is finder (6 letters).

Crossword clue: optical device that helps a user to find the target of interest

2 answers found in Letterora's clue database (Wikidata facts, Open Trivia DB, WordNet and Webster definitions — all licensed sources).

finder 6 letters wn-def

optical device that helps a user to find the target of interest

viewfinder 10 letters wn-def

optical device that helps a user to find the target of interest