This rubber is measured by it's OD ( Outer Diameter ).

All other ring measurements other than this mini post are ID ( Inner Diameter ) measurements.

This mini post is slightly larger than the 3/8" OD mini post.

Reference Numbers:

• Williams 23-6694-1
• Bally
• Gottlieb
• Early Stern 
• Sega / Stern / D.E. 545-5348-17
• Midway  

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