There was one that you clip on the baby’s diaper but I read reviews about it falling out and giving false alarms and freaking out parents, so I wasn’t interested.
The base blinks green when the sock is connecting and is a solid green when the sock is connected.
It turns blue and sings “Hush Little Baby” which is so much better than an alarm that scares you!
And if the oxygen or heart rate is low, the base color turns red and alarms.
She was napping when I took the pics below, but of course as soon as I went to take pics she woke up! How cute is she smiling as she wakes up though?!