It is a holder for 5 hex keys, the essential measurements in 3d printing.
A simple holder not to walk with loose keys scattered in the drawers.
To key 1.5 mm, 2 mm, 2.5 mm, 3 mm, 4mm.
Please, leave your opinion on coments.
RepRap Pet-g 1.75
Scale 0.5% to 1% depend of keys.