AKA octo-s. Good for OW (or as a spare second stage on SM for passing high flow restrictions due to an ability to breathe while upside down and at odd angles):

1) Oceanic Swivel 180 Octo., approx.30 dives on it, no hose. http://www.oceanicworldwide.com/p_re...180_specs.html
Asking $55 + shipping

2) Apex Egress Octo (BALANCED second stage octo), 2006, new, no dives on it, no hose.
http://www.leisurepro.com/Prod/SQTAE...%3d0%26Hit%3d1
http://www.aqualung.com/products/egress_octopus.html
$95 (LWR-48 shipping included)