Windshield Repair Forum

Recently I saw a Glassweld kit for sale on the forum.
On one of the pictures of the equipment, I saw a large suction cup which had a rubber ring type handle.
I assume that it is used for flexing the glass from the outside of the windshield.
Has anybody ever tried using one of these? Are they useful?
More info would be appreciated.

I have about 6 of them and used 1 once, I guess it helps but when flexong I just you a probe as I feel I have more control over the probe.

I agree with GlasWeldTech. Sounds like this may be one of the older sets. The newer sets - like mine - do not contain the large suction cups.