Here is what I found on Sharper Image. Looks like they have a sale going on right now, lucky for you! I started seeing new hair growth within 4 to 6 weeks. You have to use it faithfully every other day, the instructions are easy to follow. I have been using it for 11 months. The new follicles are still working and the new hair is around 6 inches long or so. More coming in. Patience is required.
https://sharperimage.com/products/cordless-hair-growth-comb