To identify the age of a vintage Koken barber chair, collectors typically use serial number ranges

Many Koken serial numbers begin with a letter, which often designates the model series:

The Ultimate Guide to Vintage Koken Barber Chair Serial Numbers (1895–1960s)

Knowing the production year allows collectors to track value variations effectively across standard reseller markets. According to archived transaction values across vintage platforms: Determine Koken Chair Age by Serial Number - Expert Guide