Of course this old heart-shaped ironlock would be perfect for locking to a bridge somewhere as a symbol of enduring love, but it's such a sweet one I think better to hold onto it! It takes a small bit of effort but the key still works to open and close it fine, and once locked, it's locked tight. I am not sure the maker, but based on. looking at others similar I'd guess it dates to the 2nd half of the 19th c. 

2 7/8" tall x 2 1/8" wide x 1 5/8" deep. Some rusting as documented to both lock and key, but very good overall condition.