I have been looking at the x4 system to check the trolling speed at the ball (its over 500.00 bucks) wow! but the td would be good for spot checking the water column and finding the inversion. the warranty says the batts are good for 5 years, can you change the batts? or send it in?, or do you have to buy a new one? I also would be interested if any body has used ether system. also here are some specs. on the td Shows the water temp every 5 feet to 300'. dfly
•Highly accurate temp sensor, displays F or C
•Shows maximum drop depth to tell you how deep copper, leadcore, or Dipsies are running
•Highly accurate pressure sensor, displays in feet or meters
•Free Elberta Clipper by Dreamweaver, a convenient way to attach TD to the line
•One-year warranty, five-year battery life guarantee
•Made in the USA
•Weight 2.72 ounces