Dimensions are D: 200 mm, height is 25 mm. 

You will need:

Fifteen 6mm airsoft bb's - for the axial ball bearing

1218GE-N20 motor - for the drive, such as this one: https://www.amazon.ca/dp/B08LL9TF91?ref=ppx_yo2ov_dt_b_fed_asin_title 

Assembly is as follows:

1. the vertical lock can be pressed into the center of the top piece
2. The bb's can be pressed into the corresponding 15 holes in the bearing ring, (they should have some resistance going in, but be able to spin freely once in place) the ring can be placed on top of the base
3. the pinion gear can be pressed onto the motor shaft (note the orientation of the drive flat), and the motor can be placed into the motor mount with wires slid into their guides. This assembly can be attached to the base, a few drops of superglue holds the motor mount in place. Reference the picture for orientation. *NOTE: the turntable works well without a motor, the axial bearing allows it to spin freely by hand if you choose not to use the motor.
4. the top piece can be placed on top of the base/bearing assembly. Ensure that the gear teeth mesh properly, and the vertical lock clicks over its counterpart on the base (this will allow transport of the turntable without it coming apart)