Why doesn't this product have reviews?

[nataliayblake0]

I'd like to leave a review on this product: http://www.ebay.com/itm/Small-Pet-Cat-Puppy-Dog-Carrier-Durable-Hard-Sided-Outdoor-Travel-Container-...

Putting it together was a little difficult, so I wanted to give people some instructions in case they stumbled on it. But there is no review button. Usually it's right below "questions and answers", and that's how it is on the other three products I bought, but not this one. Where is it?

[labs118]

There is no review button because this seller didn't enter a UPC
If you search the item by title you will see the pink carrier has a product review and so does a blue one from other sellers who have a UPC listed.
The buyers star rated it didn't write any reviews.