Pedro is very cool. He designed this one for my specifications, and I love it. I've worn it 5 days/nights without complications, and it is very secure! It's strong and very lightweight, as well. I wasn't sure about getting the spikes built into the head of the tube, but I went ahead with 2mm spikes. They're long enough to let you know they're there when aroused, but not so long that they'll cause too much discomfort. I wanted to make sure I could get something that could be worn on a long term basis, and this is it! Pedro's designs are very cool because they allow you to custom-make your own tube, to your own physical specifications, without spending a ton of money. You can try two or three different varieties and still pay less than when buying other 'custom' devices.