The Intensity, which we call a “pelvic tone vibrator,” would certainly not be harmful in any way. There is some clinical evidence that increasing pelvic floor muscle strength and tone may improve prolapse a bit, and it is very possible it may reduce the progression or the prolapse to some extent.
The Intensity adjusts for a perfect fit and then uses electrodes to stimulate muscle contractions to increase tone. It has an additional vibration function, because that, too, increases circulation in surrounding tissues and orgasm is, in itself, great pelvic floor muscle development. (Read more here about how to use the Intensity.) The makers of the Intensity recommend that you be able to insert the Intensity shaft at least four inches for effective use.