The ones I use from ebay I think are called preg now. They are 10IU sensitivity and have a blue strip at one end and are very small and skinny.
They are notorious for evap lines but I have seen my first BFP at 10DPO with my EP. IO must say it was hard to believe it was a BFP not an evap line so I then confirmed it with another test. They did however pick it up before the FR. I then had a BT about 3-4days later and BHCG was only 20 so it picked it up much lower then 20. Probably even lower then 10.
I buy them because I am a serial POASer and its just too costly to buy FR and some of the other tests available. They have caused me some heartache though when I hope what an evap line is actually an early BFP but turns out to be a BFN.