As others have said, it smells like rubber. As a table tennis player, I'm used to it;)
Who is busy with his camera and go with his motives, should be hardly bothered by it, too bad it's not.
From me, then there's thumbs up. Definitely a good investment for Use quick cleaning in between. Two, pump three times and the lens is free again.
Supplement: I have the part still, and the smell is gone for ages. I think you can at first just let air out, rather than to store directly in the camera bag after purchase.