Product review (5 stars): Exact part and simple replacement
I bought this to repair our KitchenAid blender, model KSB5WH4. I could have purchased the part from several suppliers ranging in price from $4.86 to $9 and most charged a little more for shipping. This part from Amazon does seem to be the same factory certified part as described and the package says "made in US" which is nice. Very easy replacement.

The coupler on our blender broke apart, that is, the hard, black rubber part broke apart and so only the metal core/insert remained on the blender. I read a few online instructions on replacement and then watched a few youtube videos showing the replacement. Instructions are included with this part and includes a few photos. removal of the old coupler is even easier than the youtube videos show.

The coupler core appears to be made of aluminum and is screwed onto a hardened steel shaft. The instructions require you to insert a flat screw driver under the old coupler and just pry it up a few times, rotating your position until it comes off. Because the coupler core is aluminum, it's really just prying the threads up which give way to the harder steel. Once off, you remove any bits of aluminum threads that came off. Then simply screw the new coupler onto the threaded shaft. You can and just need to hand tighten it, counter clockwise. The normal blending motion/direction tightens the coupler further. It literally took me all of 90 seconds to complete the whole replacement.