。
Everything that's mine is yours.
Literal
I [of-の] things [topic-は] all your things is.
僕のもの ('my thing') and 君の物 ('your thing') use の+もの/物 — the nominalizer pattern creating 'thing belonging to X.' Note the writing difference: ひらがな もの vs 漢字 物 — both common, the kanji feels slightly more concrete/physical. A classic marriage-vow-style declaration.