I'm guessing you purchased these off eBay - I actually saw a UK seller selling loads of these really cheap all in one size and there is a person in Hong Kong selling them too. The Baya is NOT part of the Crocs RX range as far as I'm aware the RX range doesn't come in pulse! The only ones in red in the RX range are called Silver Cloud, so I think they got the strap from there! Also the Baya doesn't currently come in red as far as I know, only pulse which is a red-orangey colour. http://www.crocsrx.com for details.
I must admit that the pulse ones that were/are on eBay currently with the hole and Crocs RX in the strap do look a bit 'shifty' and I'm kind of guessing that they're not all they are cracked up to be...the material looks a bit thin and 'cheap' compared to other Bayas with the proper strap on. They're a bloody good fake though if they are!
