I have the Penimaster Pro sitting in my drawer collecting dust for about 2 years because I was using it with very high tension.
I believe the penis head suction cup possibly has a flawed design when using under very high tension because the head suction cup consists of two half hemispheres that are glued/cemented horizontally like at “the equator”
My belief is that the high tensions I was using it at would cause minuscule seperation at “the equator” which led to air escaping and the suction not holding.
Good news is that the company graciously sent me a free head suction cup which worked well for about a week but then I started losing suction again presumably due to the high pressure I was using it at possibly causing minuscule separation between the two half hemispheres.
A+ to the company for excellent customer service in sending the replacement part.
I have lots of gels and “plastic” pieces but have not used for 2 years.
Perhaps I will place an order floor another head piece but this time NOT use at extreme pressures.