Make sure you get the next somewhere with a good return policy.
FWIW, the SI Gel Flow was a torture device to me. Used one for about 4 months.
... or have a friend like me who will buy it from you if it doesn't work -- most saddles are fine for me (and I can tell right away if a saddle's one that Won't Work)... I've about worn out the Selle that my friend didn't care for and am shopping.