Wheels manufacturing spacers for bottom brackets or freehubs. Made from 6061 aluminium and they are silver in colour I do not know why the picture shows them in black.
The 1.0mm spacer is placed behind a shimano 10 speed cassette so this is a replacment. Also can be used on external BB's.
The 1.5mm spacer is mostly used as a BB spacer
The 4.5mm spacer is placed behind a 7 speed cassette so it fits on a 8/9/10 speed freehub body (shimano type).