there are 7 different sizes of spoonplugs. the #500 runs 2-4ft deep on 12 no-bo line, bout the same dia. as 20 mono. the 400 runs 4-6ft, the 250 runs 6-9ft, the 200 runs 9 -12ft, the 100 runs 12-15ft, the 700 15-20ft, the 800 20-25ft. ya can double that depth with a weighted line (wire or leadcore). so ya can fish down to 50ft. have caught fish deeper than that in fresh water, but had to go to live bait to be successful at such depths. hope this clears things up!...FD