I bought these for my sub for anal training/ass ownership play; with the intention for her to wear them 24/7, bathroom needs permitting.
It's been a month now and it's been the perfect plug. Comfortable and flexible, doesn't easily slip out, not too big that it hurts to insert (though she is quite experienced and supple, beginners may need to practice a little before getting the last bead in, but it's hardly unobtainable). The T-shaped base fits snuggly between her cheeks and as an added bonus, the tip of the T-base gently touches and presses on the entrance to her vagina, for added teasing/sensations during her everyday activities. Easy to clean and good value for under £10.
The bumps pushing through the rectal wall feel great along your shaft during vaginal sex. She seems pretty happy with the added pressure and stimulation also.