This little vintage clasp is old, but never used, probably made in the Czech Republic.
A gorgeous piece, with a hook action clasp, where the closure needs to have the side protrusions squeezed inwards to release to release the hook, so it is very secure. However, having said that, if you are making an item for someone who doesn't have someone to help dress themselves or without dexterity, I wouldn't recommend this closure as it's a bit harder than a normal clasp to close.
Clasp features 2 loops on either end for a multi-strand piece, with 5 rectangular shaped diamantes across the centre, each measuring approximately 4x2mm. There are another 8 tiny crystals (clear) adorning each side of the centre settings.
Measurements: 23mm long (including loops) x 11mm wide.
All the diamantes are slightly yellowed from age (see photos) - a true vintage clasp!