“Come in spinner” is a term that is associated with the game of Two Up. This is a uniquely Australian game in which bets are made on the chances of two coins falling with either heads or tails landing face up.
If you do the maths, then the chances of tossing a head or a tail should be 50/50. In reality this may not necessarily be true.
You should probably visit the link to “Adjustable Spinners”.
Oh…and don’t forget to do the maths!