Since these nipple clamps are not adjustable, I was worried it may pinch too hard or be an issue, but the pressure is light, but firm. The vibrations are strong. I only used the lowest vibration setting anf it was so intense, I loved it! It did take me a few clamps to figure out how they go on, but once I did, they stayed on well, even with me shaking my boobs around lightly and lightly flicking the nipple clamps back and forth. To put them on properly, hold the clamps where the mouth is facing upwards and clamp your nipples from below. I also love that it is app controlled, which will be very fun to use long distance with my Dom. These are my new favorite nipple clamps. These will definitely give me many more nipplegasms.