What is the one call that you own that if you left home without it you would be willing to turn back for?

For me it has surprisingly become a Primos True Triple mouth call. I could run my trusty pot calls but without my mouth call I feel lost. I can go with nothing but a mouth call.

It's only be the last 6 years or so that I've gotten this way. For a long time I had to have an old Lohman ThunderDome. Before that it was a box call.

What about you?