I mentioned this in passing a while back to Nemrod and others. I like to use the older USD second stages (the one with the small exhaust valves) as alternate second stages. I use Bryan's miflex hoses in 40-48", and I set the cracking pressure to about 1.5 inches. Then, I take some snips and cut the exhuast tee down, and I also use the regular black mouthpieces that Bryan sells in the store to have a minimalist mouthpiece. I have been using these for a while, and they are very effective. If you use a 48" hose, then you can run the hose under the waist band of a VDH backplate so that it pulls free when deployed, but is tucked away when stowed. Think of it as a tiny long hose, but not wrapped around your neck. You can get these second stages for like ten bucks on the internet, then purchase the hose and mouthpiece, as well as any rebuild parts, from the VDH store. It is a cheap, durable, and classic looking setup. I much prefer it to those yellow ABS octos that get all faded and eventually crack.