It is an interlock kit, but the one I have is made by GE for my GE panel: »
www.homedepot.com/h_d1/N ··· Nzmf5Wb0The ones you linked to are third party aftermarket interlocks. I'd look to see if your panel manufacturer makes one specifically for your panel... it's the best way to go if available. Either way, check with your local building inspector before you buy to make sure whatever you install meets local codes. Mine was approved without issue.