Swallow Cardigan Clips by Jubly Umph.
Here's what Jubly Umph have to say about their awesome cardigan clips:-
"Cardigan clips, also known as sweater guards or collar clips, were popular in the 50's and 60's to keep your sweater or cardigan closed and for cute decoration.
Jubly-Umph cardigan clips feature a double chain and strong alligator clips."
- Clip size: Approx 30mm
- Chain Length: Approx 140mm