Has anyone heard of this Ultrasonic Sensor?

The model is SP-40-38F. You can find it here: http://www.cutedigi.com/product_info.php?cPath=278_295&products_id=4282&osCsid=d133de8082a4556d02f27cdf248ae912

I would like to buy a few but after looking at the site, I am a little hesitant to send them any money.

Thanks,
Brian