I purchased the Grille Eye Pro and absolutely love it! It has 8 inputs! The only problem I found with using it with my FEC 100, is the FEC is stainless and the Grille Eye Pro magnet won't stick to it. I also found that I could purchase cheaper additional probes instead of the Grille Eye Pro probes. Amazon has a 4 pack of additional probes under the title of 'Cookingstar 4 pack meat probe" for $37.99
that work perfectly with the Grille Eye Pro. The Grille Eye Pro probes are $20 each.