SeaSense EASY LIFT JACK - any experience?

[gsxseadoo]

has anyone used this thing on a jet ski trailer? for $15 it seems like a great concept and much easier than a traditional jack. my concern is if it will work if the tire is flat. another concern would be jacking up on the axel cause issues?

https://www.amazon.com/SeaSense-Tons-Easy-Lift-Trailer/dp/B000FZ345S

demo of a similar model

 

[gsxseadoo]

bought one to try out and its going back. tried it on the garage floor and it would just push the thing on the the floor. may work on dirt as the teeth would have something to bite. it is also a bit bulky. will be just carrying my scissor jack and use the trailer frame for lifting.