I've never had an opportunity to use this.
I bought it years ago, and I paid over $250. (I remember wife freaked out.)
This is the model that you rotate the arm back, and it rotates down little feet that lifts/locks you onto the pavement.
You roll under, get to be where you need to be, pull lever back, and you're not going anywhere.
If you need to torque on something, you're stationary and won't be fighting rolling around, because you're locked to the pavement.
When done, you simply push lever forward, and you're on wheels again.
It was the absolute BEST at the time and I thought I'd use it all the time, but due to health problems never did.
"CraigsList Email" me, [purple "reply" box, upper left] and I'll get right back to you ASAP.
I can't be calling or receiving calls from anyone. My phone number is for my official work only. So, no phone number available.