Never guess a Brook or Rainbow Trout weight again. The award winning Brook & Rainbow Trout Release Ruler is the must have for serious Brook and Rainbow Trout fishermen. Release Rulers are patented as the only ruler to provide weight and length estimates of fish on the same device, pairing length with color-coded weight brackets that make for instant weight estimation and great pictures. Simply measure the overall Brook and Rainbow Trout length, take a picture and release. The Release Ruler’s contrasting colors estimate the Brook and Rainbow Trout weight based on scientific growth charts. The ruler is durable, tear-resistant, easy to stow and charts weights from juvenile to HUGE!