Package contains:
32 x cap shaped key covers
32 x ring shaped key covers

Use key cover caps to colour code the doors, solved the problem of all those keys getting mixed up.

Multicolours: red, black, white, orange, yellow, purple, blue, green ...
These are made of flexible rubber. They can be stretched.
The cap size (before stretching): 17mm x 23mm x 4mm ( length x width x thickness ).
The ring size (before stretching): 22mm x 4mm ( diameter x thickness)

They fit most of standard keys, like round end keys, triangle end and hexagonal end keys.
★ They do not fit for modern doors have keys with large square ends.