Bluefin Tuna RulerThe award winning Bluefin Ruler is a must have for those of you targeting the mighty giants of the ocean. Simply lay alongside your tuna and measure. The Release Rulers contrasting colors estimate the bluefins weight and age based on the scientific growth data. The ruler is durable, tear-resistant, easy to stow and charts weights from juvenile to HUGE! The ruler is made from PVC vinyl, measures 2 wide (5 cm.) x 125 (316 cm.) length. Release Rulers are available in both imperial (inches) and metric (centimeters) units of measurement. Each ruler is true to scale and dimensionally stable.