I have had one on the engine in my Edge since new paid $250. ...You can see the black top just over the top of the right header in the picture...
It works well and I have never had a problem with it....It is especially nice when the engine has not cranked in a few weeks ...or months...and you can see oil pressure on the gage before you fire it...
The downside is that its a one shot deal...as you must fire the engine to refill and pressurize the cannister.
If I had it to do again I would buy the one Keith Eickert sells instead...a little more expensive and a little more complicated install but he uses a pump which you can run for as long as you like ....and use it for cooling after a hard run....
Keith Eickert.. (http://www.keith-eickert.com/)
http://www.***boat.com/image_center/...60DSCF0059.JPG