Sounds like you might have a KarKAttySS by Demco.We have one also and love it. Just be careful not to go up and over it like I did!!!
And it wasn't the first time I loaded it
Other's have told you how to use it. I might add that its almost impossible to back it up, so don't go into a lot with out making sure you can get out without having to back up.
Happy travels, Tim