These seals fit on the body.
I have been selling these Seals for about 10 years now (over 900 sets sold ), if your windows leak when closed then these are possibly what you need in your life.
Results have been great with these, some people find they stop all leaks and some have found they are far better than what they had previously. If your not 100% satisfied with them, then just bag up and send back for a full refund, no quibble.
(Seal is produced in Germany)