The diaphragm are tight so during the first couple of night or when your not wearing the pro do this to break them in faster.
So tonight when you take it off use the ball pump and cause suction on the diaphragm with out u inside it leave it like this over night to stretch it out.
PUTTING THE PRO ON IN A COUPLE OF EASY STEPS.
STEP 1) remember to cause negative pressure when putting it on. so why is negative pressure important 1 it cause a bigger vacuum in the chamber causing the head to go in easier and the other 2 super important reason is when the diaphragm pushes out you push the head in this causes a seal and less air between your head allowing less chance of fluid build up in an empty space between your skin and the diaphragm.
3rd reason it cause a seal in the sluice so you don't get build build up on the shaft behind the head. remember you want the least amount of space then causing a seal. empty space will fill with fluid due to vacuum pressure.
so only have the ball pressed half way then attach the ball press the ball the rest of the way causing the diaphragm to bulge out of the sluice then press penis firmly on the penis head to bulging diaphragm causing a seal then release pump about a quarter to half the head will go into the pro,
STEP 2 Then unscrew the pump just enough to squeeze the ball pump completely all the way down and screw back on press head piece on to head and release ball pump it should go all the way in if not repeat step 2.
TIPS: Allow the penis head to swell in the head piece after you have it on. Tighten locking valve not to much just a quarter turn if you turn it hard you will crack the stem. then allow 30 sec to a min for the penis to head to expand in the chamber.
Then pull on it see if its secure if not repeat ball pump to increase pressure. As well i let 10 second go by even after the ball returns to its original state as there is still pressure that is causing expansion. Then do step 2) also i find that if i get to the point were the ball doesn't go back to original shape that is were i want it usually this is the third pump squeezes. Hope this helps anyone having issues or who just got the pro.
i wish they would make a see through version of the head piece as his would allow us to see the head expand.
REM just to let you know i used the extra pieces and now with use of the [words=https://officialhydromaxpump.com/?uid=6&oid=2&affid=98]penomet[/words] and the constant swelling of the head in head piece i have moved up to the large sluice and can't used the the reg one anymore. so keep at it. the numbness might be caused by the tight sluice. if your girth is 5 inches around hard and max 4.75 soft or below then the sluice will cause mild discomfort but if you are above that then you have to goto the large sluice.