8 or 10″ choose from the drop down

10″ 3/8″ thick spacers

OD is 10.67

ID is 9.13

8″ 3/8″ thick Spacers

OD is 8.64

ID is 7.26

Will work to spacer speaker out in the nagy ring, use for mounting speakers on the face etc. Will not work in the SBD lids unless you router them down to an OD of 8.24