I have plenty of experience dealing with ball suck, usually with cylinders that are slightly too big in diameter. The extra tightness at the entrance when using a sheath should reduce ball suck unless you pump to really high vacuum pressures.Thank you man. And that won't effect my dick cuz I'm thicker than 6
Otherwise you'll just have to wedge the cylinder base firmly between your balls and cock underside, press firmly as you pump so that the skin isn't sucked in too much, I had to do this with my Bathmate Goliath which was way too big for my cock.