Smooth Operator
The Smooth Operator is a Toggle-type releasable and retrievable advanced anchoring device designed sold by B-G Gear. Using a Smooth Operator is a ghosting technique as in normal use it leaves no artifacts behind. It has a few features different than other available Toggle-type devices.
Documentation
BluuGnome documents the Smooth Operator on his site, including basic usage, detailed usage, and how to make your own.
Safety System
The Smooth Operator is usually "locked off" with two locking carabiners. Each carabiner is clipped through a hole at either end of the toggle. The safety system is removed by the last person prior to rappelling. Some people use a locking quickdraw (a short sling & two locking carabiners); clip each end of the quick draw to the ends of the toggle.