Removing object from bathroom sink

[Truckee05]

So my wife was removing her earring tonight and dropped it down the sink in the bathroom of our fifth wheel. I went under the sink to remove it from p-trap only to find there isn’t one. I followed the plumbing back to a white canister looking thing that has a flow direction arrow on it. I’m assuming it’s some type of flapper valve to replace the p-trap. I am hoping it is strong enough to hold the earring till I can get tools tomorrow to undo all of the fittings and get into it thanks to all of the plumbers paddy. If it is not there any suggestions on how to get the earring out or where it may be? I am pretty mechanically incline but don’t want to tear the trailer apart looking for this earring. At the same time I don’t want to have to take it to dealer 3 hours away to have this earring removed.

Thank you in advance.

[Grumpy]

It is a one way valve. Only other way would be to screen all the grey water when you dump hoping it flows out.

[Chrisb-24]

Fill the tank with fresh water then screen the hose when dumping.
Good luck on your ear ring search!
Chris��