Gold Bug Pro /Gold Bug DP??

What is the difference between the Gold Bug Pro & the Gold Bug DP/ . There is approx 100 dollars diff between them.

Pretty sure there is no difference in the actual detector but the:
Gold Bug Pro comes with 5" coil http://www.fisherlab.com/hobby/fisher-goldbug-pro-metal-detector.htm &
Gold Bug DP comes with 11" coil http://www.fisherlab.com/hobby/fisher-goldbug-dp-metal-detector.htm

Hmmm.
Mine came with an 11 in DD and a 5 x 10 DD. So maybe that makes it a Gold Bug Pro/ DP .5 

If it's the one you posted here: https://golddetecting.forumotion.net/t24704-which-is-the-best-discriminator-detector-for-shallow-gold#240559 it looks like an aftermarket Detech SEF 10" x 5" coil for the GB Pro/DP so I guess that could make it a Gold Bug Pro/DP .5 Looks in good nick too. They are supposed to be a great coil on the GB.

The 5 x 10 SEF is excellent and going by first impressions  I think it is close to the 11 inch for depth. It definitely more sensitive to most items I have tested it on so far. Response is very sharp and provides some useful extra separation between close targets.

I used the 11 inch on my previously stolen Gold Bug and it is a very good beach coil for coin and jewellery with good coverage. The 5 x 10 has impressed me a lot and might eventually take the place of the 11.