What is the thingie on the WBT Bananna Plug


I am looking at getting some bananna plugs, and in particular have noticed the WBT model 0645. It looks like it has an insulator or something plastic that protrudes from the front parallel to the bananna extrusion. Anyone know what this is? Looks like this will prevent the bananna portion from going into the receptacle, will it?

Also, any comments on this plug, where to get it, or other comparable connectors. Please, Bananna only because that is all my speakers will take, the have 4 bananna holes per speaker (no "spades are better" please because I can't use them).
Here is the wbt cite

http://www.wbtusa.com/wbt0645.html

Thanks in advance for your helpful comments and/or jokes!
south_park
The "insulator" is to prevent inadvertent installation of the banana plug into a type of 240 volt wall outlet common in Europe. Sort of an attempt to appease some "big brother" government regulation.
Alexander is correct. It has to do with laws particulerly in Germany to prevent them from being plugged into an AC outlet. Another protection device for children and real stupid people. Mine would not insert fully on my Legacy speakers. So I cut the plastic rod off and dressed it with a file. It is a perfect fit now. As far as resale goes I plan on keeping them. Sound wise the 0600 straight rodium top line bannas sound better.
Hi, I forgot to mention that Parts Express sells WBT connectors at the best prices I have seen. Go to their web site at WWW.partsexpress.com . Good luck!
Gunbei, you have got it right, and Motorpsychos I think has the solution I was thinking of, its good to see people with the same problem at least. No reason performance wise not to cut the plastic dealie off and use it anyway.
South_Park, isn't this great? In true Audiogon fashion, Alexander and Motorpsychos have solved your problem! Have fun.