Megan lower tie bar, mounts under the back between the rear lower control arms to stiffen up the chassis. This one is blue.
This bar was installed, but never driven on. I decided to go with a different design because it interferred my my homemade/hybrid swaybar setup. I bought it for my DA Integra, ended up putting it on my CRX, then took it off, so it should fit EF/DA/EG/DC, and maybe EK.
$60