Imperial System:

  DIAMETER (inches) LENGTH (inches) WIDTH (inches) THICKNESS (inches)
Round 8 ¼
Rectangular 9 ¼ 7 ¾ ¼

 

Metric System:

  DIAMETER (cm) LENGTH (CM) WIDTH (cm) THICKNESS (cm)
Round 20.32 0.63
Rectangular 23.5 19.7 0.63