The components and the quality of this product are excellent. Learning to use them effectively is a different matter, especially when one has never had this issue previously to address. However, the instructions are clear, even if the execution by the user may require experimentation and practice. Patience is important. Persistance is vital until a satisfactory result is achieved. Every body is slightly different in psyiological response, so combining how your own body responds to various stimulus and adjusting the mechanical tools to take advantage of physical response is the key to success. Learning which button on the vacuum pump does what is essential, particularly when personal objects are drawn into the vacuum tube and produce abrupt distress. The (-) negative button and the "AIR" buttons are key to releaving unexpected stress. Pain is a great teacher, so once you make the error, you probably won't repeat it. Depending on the user's physical response, they may identify that using the tube to install the rubber ring is sufficient to achieving the desired result. Like everything else in life, subsituting a mechanical solution to mitigate a physiological challenge is not the most desirable approach, but when the body will not provide the necessary controls, due to chemistry (medicines that treat other body issues but compromise retention of enflation), age, or whatever else is necessitating the use of this mechanical tool, the possibility of achieving a working resolution is preferable. Remember, the electric (battery operated) vacuum pump is very efficient and it only takes a few seconds to reduce the air pressure inside the tube (assuming a good seal is obtained at the open end). Don't be in a hurry - slow and steady - or you may find the immediate result undesirable. A sea-level, air pressure on planet earth is about 15 pounds per square inch (Standard sea-level pressure, by definition, equals 760 mm (29.92 inches) of mercury, 14.70 pounds per square inch, 1,013.25 × 103 dynes per square centimetre, 1,013.25 millibars, one standard atmosphere, or 101.325 kilopascals.

Very pleased with this product. Surgery in Feb. 2020. After several weeks of practice have been able to achieve a firm and full erection, Has really helped my confidence about continued recovery going forward. Highly recommend.