Usin' a Jasper Model 200J Circle Jig with a Dewalt DW618PK Plunge Router: 

• LOC/Precision 3.90" Diameter Tube
• Outside: 3 7/8"
• Inside:
• LOC/Precision 5.5" Diameter Tube
• Outside: 5 13/16"
• Inside:

 T' settings above create rings that require some sandin' t' fit.  If you would prefer lose-fittin' rings, add 1/16" t' t' outside settings and subtract 1/16" from t' inside settings.