While my Merkur Vision 2000 is in the shop for repairs, I have reverted to my backup razor, a Gillette TRAC II. I bought a few months worth of cartridges on eBay, but when they arrived I realized they were the wrong item. They must be for the ATRA or Sensor handle, but I am not sure which one. Now I have to get a handle to fit these blades or toss them and buy one of those five bladed things that are the current standard. My question is this, will cartridges for the ATRA fit a Sensor handle and vica versa? I am grateful for any assistance.