I have been struggling with the sluice sizes since I bought my [words=https://www.internetzahlung.de/cc-aktuell/bestellung.php3?PID=PM0440A&Sprache=en]PMP[/words] . I have a friction sore on the top behind the coronal ridge . The sore gets the worst abuse when using a strap at work in my Kitchen . It must be the angle where the [words=https://www.internetzahlung.de/cc-aktuell/bestellung.php3?PID=PM0440A&Sprache=en]PMP[/words] attaches to the strap and the tightness of the sluice . In the bar setup I still get it but, I have devised a solution to make the bars safe and a guy named Nash from P.E. Gym has pioneered the use of latex balloons for all of the wear parts in the [words=https://www.internetzahlung.de/cc-aktuell/bestellung.php3?PID=PM0440A&Sprache=en]PMP[/words] . Here is a link to his thread and his album for picture of how this can be achieved, http://www.pegym.com/forums/groups/penimaster-pro-d576-latex-baloon.html and http://www.pegym.com/forums/members/nash-albums-use-latex-baloon.html . My solution for the pressure is for one to put a rubber band over the the shoulder of the [words=https://shop.mattersofsize.com/products/sizegenetics-penis-extender]extender[/words] while it is connected to the bars then when one puts the glans on the shoulders the rubber band will not allow the chamber to dip down and alleviate the pressure . The shoulders or MSP Concept calls it the coupling socket , the rubber band would slide back to be even with the ridge on the glans chamber that the diaphragm secures to. The latex balloons are really awesome , I cannot comment on how long they last but, so far MSP Concept cannot touch its comfort. They are not twisting balloons as Nash explains they are just regular round . I am presently using a 9 in. for the diaphragm and a 12 in. for the sluice. I ordered larger balloons for the sluice but , the 12 in. ones I got from PartyCity ate near perfect. You need to check out his album to see how to attach the 9 in. to the glans chamber , no mods are needed just cutting the balloons. As the balloons get larger the neck (A.K.A. the mouth piece) get larger too , each company is little different. I just ordered from http://www.balloonsfast.com/ , they sell professional top quality balloons from Tuf-Tex and Qualatex . I will post later if there is any difference in durability and comfort. Good luck