This thread is sure funny. Now some are looking for the thingy to keep the door propped open.
Mine did not come with one and since my fridge is along a side wall I don't need one. I simply make sure the trailer is not sitting level by just enough that the open door stays open by itself - wide open for maximum airing out.
To the OP - I keep a box of baking soda all the time in the fridge (home or RV) and in the RV fridge I have a battery-operated fridge fan. When I get home I turn the fridge off, empty the fridge, dump all ice cubes down the toilet, and leave the door wide open a mentioned before. No issues, no smells.
I have a set of the Dometic blue tabs. I was merely questioning the original premise that most or all had something built in to hold them open. The Dometic tags won't hold the door securely in transit but are fine when parked.
It's a door spacer to allow the refrigerator to air out when not in service. That middle finger fits in the V of the latch on the door. Insert from top down with the wide area of the thing toward the refrig.