- Precise design: Combines an accurate scale with fail-safe calibration to deliver precise head circumference measurements while ensuring a comfortable user experience. - Palm-curve adaptive grip: Ergonomic, anti-slip handle that conforms to the palm curve for fatigue-free handling over time, and ensures precision with an automatic rebound design. - Premium material: Made from high-quality material, this hat ruler resists deformation and oxidation to maintain long-term accuracy, with a wear-resistant finish that preserves a durable, polished look. - Practical tool for production: Precision-integrated manufacture and pattern optimization improve workflow efficiency while capturing accurate inner diameter data for consistent performance of hat production tooling. - Applications: Ideal for millinery shops to accurately size customers, in hat manufacturing to capture inner diameter data for tooling, and for custom hat fitting or alterations to ensure consistent fit.