To Jelq before you pump, Have full erection when you pump.
This process will result in a harder and bigger erection within a few minutes.
With jelqing before and between sets.
Also, you need dedication to see results.
The mouth of the penis pumps has a bellow gaiter made of silicone which ensures an airtight seal with the pubic region.
And if one of those main four categories of problems that result in sexual dysfunction, blood flow or vascular issues.