Wagner's pessary is a pretty simple, if a little bit cursed, piece of kit. You pop it in the vagina, inflate it, and it sits there supporting the uterus. It has an extra pipe coming out of it to conduct menstrual fluid.
Now, we've shown you a cursed old-timey inflatable vaginal doohickey before*, so what's so special about Wagner's that we have decided to doom you with the knowledge of it today?
*here, ICYMI https://masto.ai/@vagina_museum/112122667010921975