@thomasj1 this may seem a bit strange but, I started with a pump that my urologist in 2008 arranged with a salesperson at my urologists office. That pump eventually failed and I wasn't willing to pay their price for a new one. I'm pretty resourceful and I decided to build my own. I already had a hand operated vacuum pump so i made one from PVC pipe and an arrangements of fittings to accommodate the pump hose. It works great and I've been using it for several years. I do use penis rings I found on Amazon plus a penis ring vibrator that goes next to my penis ring and vibrates against my scrotum. I also use 100 mg. generic Viagra. The combination works very well and I can maintain the erection for 30 to 45 minutes.
Im 82 and married my wife 2 years ago and we have a very happy sex life.