Consider this to almost be an educational video for aspiring pelvic spelunkers.
Denni O opens Joclyn Stone wide with a large speculum to provide extremely graphic close-ups of various dildos and other apparatus going in and hitting bottom. While some of this is repetitious and a bit boring, some crazy stuff does happen: Denni pours milk into her opening, runs a hose down into the liquid, and blows milk bubbles.
Mishka 38G receives the same treatment. Afterwards, she and Stone get into some dildo play and more close-up coital contact.