Tank boot

[rjoe]

Looking for a tank boot for a 45 min carbon fiber tank. My try at measuring the dia. of the tank came in between 6.5 and 6.75 inches. The tank on ebay that comes the closest to these numbers is for a steel tank with a rounded bottom for 6.9 inch tank. It cost about $17 or $18. Is that the right one or is there a better option? All help greatly appreciated. 

 

[Humdinger]

Measure the circumference of your tank and divide by 3.1416 to find out the exact diameter.

 

[rjoe]

"Humdinger"Measure the circumference of your tank and divide by 3.1416 to find out the exact diameter.

That method came out at 6.72", using two squares came in at 6 5/8ths. So the question is what tank will work? Is there a boot made for the carbon fiber tanks? Will the 6.9" tank stay on?