has anyone of you used aftermarket speedo (NOT the swim wear) calibration units? If so what brand? How much was it? And of course was it worth it? I did a search but came up with everything i wasnt looking for.

 

http://www.fastq.com/~sschaefer/speedo.html

Dakota Digital

 

That's the one I use. I've only had it on for about two weeks now, but it is working perfectly so far. Ask around, I bought mine from someone on the TTORA forum and saved some money.