Is it der Bund, or das Bund? If it's masculine, the plural changes to Bünde, but if it is neutral. Related question: what do you call your set of keys? der/das Schlüsselbund?
Schlüsselbund mit Buchstaben Grafik, Rund & Buchstabe Anhänger | SHEIN Schweiz
Kuh Plüsch Schlüsselanhänger 10cm - BazarOuchy
KEY-BAK Einziehbarer Schlüsselbund für kleine Switzerland | Ubuy