Clear, easy-to-read scale and action line indicators for quick reference. Guitar ruler with additional practical features including a string diameter scale and scale-length measurement for expanded measurement capabilities. Measures the distance from the string to the neck to accurately determine string spacing. Constructed from strong, durable metal materials designed to withstand demanding conditions and repeated use. 2-3 concrete use scenarios - Home setup and maintenance: use when adjusting action height, checking string gauge, and confirming scale length to optimize playability. - Professional repair or custom setup: use in a workshop to precisely measure string spacing and related dimensions for nut, saddle, or neck adjustments. - On-site maintenance during gigs or tours: use on stage or in transport scenarios to quickly verify spacing and action between performances.