baby moon caps

my neighbour gave me a set of baby moon caps for my truck but it didnt come with any hardware to put them on..  what do i need to installed them.. the moon cap doesnt cover the whole rim, just the middle portion of the rim.i guess i can ask him as well  but if anyone knows on here  it would be helpful.

The baby moon style center cap usually clips onto the rim. Certain styles of steel wheel have little raised areas stamped in that the cap bites on to. The wheels on my hilux are like this to accept the stock center caps, so are the steelies on 1st gen S10/S15.

it all depends on the wheels, some have the dimpels on the inside some are on the outside for mounting the cap