Yesterday's Thing of the Day is a CAPO. An abbreviation of capodastro, & several other variants. It acts like a moveable finger across the neck of a stringed instrument, & is used to change the key in which the instrument is played.

This one is an original Schubb, which I have had for many years, & is still widely used. Most parts are replaceable.

Image from the Schubb website showing it in use.

To those who got it right. Well done and thanks to all who joined in. Another TOTD soon.