It works well
Delivery took just 3 days from my web order to my home in CA.
The pump works well. In addition to siphon action you can also have true pump action by squeezing the bulb, regardless of the relative height of the output.
I transferred 4 gallons from my 560SEL tank to a can in 3-4 minutes- using a mixture of siphon and pump action.
I replaced the hard blue output tube with 3 feet of 5/8" ID flexible vinyl tube to make the whole thing more workable.
No parts were affected by gasoline.
The path down the filler neck to the gasoline reservoir is tortuous and I doubt the 'shake to get a siphon going' action of alternate products would be easy to use given this complication with all its added friction.