
While the pix I am showing is not the one in your link (Etrailer pictures do not hot link very well) that looks like an extremely sketchy and absolutely dangerous device.
Are you on 100% flat land?
Any slight slope and you will find yourself easily outmatched by even a several thousand pound trailer.. Once it starts rolling, not much a 200 or 300 lb person will be able to stop..
Even on absolutely flat land and on concrete or asphalt, do you really feel confidant that you will be able to even start to roll several thousand pounds?
I use hand pallet jacks all the time at work, on concrete which is flat and level, it is back breaking work to move a pallet weighing over a thousand pounds.
This device has no brakes, depends on your own body weight to lift and hold the tongue.
Unless it is an empty boat trailer, these types of devices should be passed on.
Really, if you must hand move your trailer, you WILL want some sort of electrically powered mover WITH BRAKE CONTROL.
Otherwise, I would suggest a decent lawn and garden tractor with a hitch or put a hitch on the FRONT of your vehicle..