Given my positive experience working with Male Chastity Now (http://malechastitynow.com), I really have to give them a good review here.
I purchased a contender from MCN - it was shipped a day later, and arrived in my mailbox (in the US) a mere 4 days after purchase. I followed the sizing and fit measurement instructions on the MCN website to the letter. Fit is perfect, in every way. It is snug when i am flaccid, and when I attempt to get an erection, it is merely full without any pinching or pain.
The only problem I have had with the device is pain at night - and that is hardly a device-dependent problem. However, after only a week of use, that pain has already gone. I have now been locked for 6 days straight. I am free of the following common problems:
tightness at the bottom of the scrotum, and
In addition, because of the design of the device, i have access to the head of my penis, which allows me to apply lidocaine cream to my sensitive areas. This allows me to prepare to serve my wife without first being unlocked, which is ideal.
I have one single modification that I use with the device. That is, I use a shoe-string, tied around the locking post, to hold the device close to my body throughout the day. This works very well to me, and is extremely low maintenance.
Prior to ordering a MCN contender, I have gone through four cheaper knock-off devices, which all failed in one way or another for me. I was concerned I could not find a device that would work. I was hesitant to spend the several-hundred-dollars for getting a custom device. If this describes your experience, I can't possible recommend MCN enough.
The craftsmanship is excellent, the service was professional and extremely fast, the fitting instructions right on.
If you're thinking of purchasing a custom device, and considering a MCN Contender versus another brand, or versus giving up on the whole enterprise, I can't possibly recommend MCN enough.