File:S3 - alu spacer .375in OD x .257in ID x 0.3125in long.jpg

Shapeoko 3 - Aluminum Spacer Imperial: 3/8″ outer diameter (OD) x .257″ inner diameter (ID) x 5/16″ long

Metric: 9.5mm outer diameter (OD) x 6.5mm inner diameter (ID) x 7.9mm long