I've used all the big 3,penns were good,were my first elect., used them 2 years,thats when they stopped making elect. for a while ,so I sold them, had a chance to prostaff Cannon-bottomline,they gave me 3 mag20's......I HATED THEM, the up-stop-down switch sucked..after a year I gave them back,but I bought the Tourn.Master fishfinder..great unit. Had a chance to do Scotty's guide program,got 3 elect.,4 years ago,still use the same one's........GREAT UNITS....BETTER THAN MAG20s cost about $300.00 each less, thats $900.00 saving's.