Thread: How do you say, "Engagement Ring" in Russian?

I'm going to be going overseas soon and plan on proposing to my girlfriend. I want to hide the ring in my carry on inside an envelope with a note on the front that says:

"This is an engagement ring, don't ruin the surprise!"

I will be going through security that speaks Russian so how would I say this? If that phrase is too complex, how do I say "engagement ring"?

Thanks so much!

В России, насколько я знаю, нет понятия - "кольцо для помолвки", только "обручальное кольцо"