Simply rotate the wheel up or down to match the weight of the fish that you put in your livewell. Pick any scale you want to use match the numbers in tenths, ounces and hundredths. 9.99 is the highest weight recorded. Please note that your livewell may vary in size. Please measure for fit. Find a secure spot in your livewell lid (the suggested mounting area). If your livewell lid has insulation remove a 4 1/2" x 8 1/4" section to allow room to mount the cradle securely to the lid. Take the cradle and apply the 1" VHB Tape to four individual spots on the cradle. Peeling off one side of the tape apply to the cradle and once set, peel off the backside and apply to th eclean and flat dr area of livewell. Allow 24 hours for 100% set up.