I had to check my order history before writing this, and I have owned my set of these balls for SEVEN years now. I think they're officially my longest-lasting toys short of my Hitachi, and that's only because I use the old wired ones and have separate ones for massage and for *fun* massage. These balls are truly great, whether you're just starting out with pelvic floor exercises or just want to stick waggly balls in you. You can use just one or several, with or without the included little ball-corral harness they squeeze into. If you're using them vaginally, it's not like they can go anywhere, although it's totally normal to accidentally the cordless ball and need to go to lengths to remove it. We've all been there, right? ... Right? These balls are tons of fun because inside the plastic ping-pongs are big, rattly, weighted balls. The pink are the lighter weight and the blues the heavier, and you can play with combinations as you find what feels best and as your kegels strengthen. Even right off the bat, most people will be able to keep even the blue balls in-place without slipping -- they're really not all that heavy, and that honestly doesn't lessen their awesomeness one bit. They're bigger than most metal kegel-specific balls, definitely ping pong ball sized, so it means even running around naked carries very little risk of dislodging them. As you move, the outer shells will stay put, but the internal balls will rock and roll and rumble inside of you. There's plenty of sensation even just hanging out on the couch or in bed, but if you really want some fun feels then walking around, running, jumping and dancing really ramp the intensity up! Remember that Hitachi? An external or internal vibe is an amazing pairing with these as it makes them go absolutely wild! Two balls generally make it so that nothing but really bullet vibes will be possible internally, but they're more than enough! They aren't loud at all. Once they're all up in your business, you feel them more than hear them. In dead silence you might hear them if you're in the same bed as someone actively using them, but it's not something that would wake you up or could be heard over a little fan's noise. Music, tv, any conversation etc, there's no way anyone can tell you have them in which can be lots of fun, and they're not SO big and are all smooth round shapes that you can keep them comfortably in you for several hours once you've used them a couple of times. Tons of fun for clubs! You also get a great buzz with these from a vibrating butt plug. My favourite has been wearing them while out at a club or other venue with lots of throbbing bass. Public transit, while way less sexy (for me, ymmv), would also do the trick. These balls themselves should definitely not be used anally, they're too small and the retrieval cords too shory to make it possible. Honestly, despite them being so sturdy you can stand on them, I wouldn't trust the cord staying fixed even if you had it tied to a tree branch. I've not had either cord break in 7 years, and they're woven nylon so quite sturdy, but these things are the exact right size to ensure a quick trip to the ER if you try to put them in any hole deeper than 12" or so. They're also a choking hazard, come to that. They're sturdy material that cleans up easily, the ball corral slipping off easily to be washed, and they're all materials that won't rot and play nicely with water. They're some of the least finicky toys I own as I just give them a wash with soap and water and then toss them back into the included box (keep it, it's excellent storage!) without having to worry about inappropriate toy touching happening while they hang out in the tacklebox. Toybox. Tickle trunk. These were my first Lelo products and started me on some very fun and pleasurable adventures, with more toys by the same company joining me through the years. I'm honestly gobsmacked it has been this long and they're still like they are brand new, no little cracks or crevices to get vagoo in them. They've survived 7 years, 4 moves, 3 cats (who would like nothing more than to play with these wacky-rolling balls I am sure!) and a dog that loses his absolute mind over anything vaguely spherical in nature. No I do not let him know they exist. He might actually crack one, he's been known to eat basketballs and crack walnuts while playing with them. I've found Lelo products to be very sturdy and reliable, occasionally brilliant, and always in need of a good sale or coupon code. For that, though, Pink Cherry provides. PS, when getting started, lube is totally your friend! I find these make it so that no lube is needed for anything after playing with them, and I've had plenty of orgasms with just them and an external vibe!