How big is glass marble suitable for checkers game machine?

How big is glass marble suitable for checkers game machine?

Marbles come in a variety of colors. Different materials make different colors of marbles. Among adults, there are also people who collect marbles as a hobby, either out of nostalgia or out of appreciation for art.
In one play, a line is drawn on the ground, a hole or holes are dug in the ground in the distance, and players pop marbles at a time through the line. After the player has shot the marble into all the holes in turn, the marble can hit other marbles. If you hit another marble, that player wins; The holder of the hit marble is defeated. Some places just bet marbles, one at a time. Another key rule is that if a marble enters a hole or hits another marble after entering all the holes, the player can play another marble.
The second play differs from the first in that there are only lines and no holes. All marbles start with the ability to "kill" other marbles.
The third way to play is to build a ramp with wooden boards or bricks and roll marbles down it in sequence. If a subsequent player's marble rolls down and hits another marble, that player wins, and the hit player loses.