Sizing

Sizing does not affect how well devices stay on, washing with the wrong soap is the main cause of slippage. use cheap bar/lye soap!

Car-1:

You want to order the size that is within 2.5mm of what you measured yourself at. You need to be ci2+ minimum. It will not cover the glands, it doesn't need to nor will it need a frenulum notch.

Silicone retainers:

Order a size down. You want more skin to skin and less device to skin contact. Once again it will not cover the glands and doesn't need to. You will need free skin to use it. If you want to use it overnight you will need to have at least FEC ( forced erection coverage ).