• Price is per foot
• 2 to 1 shrink ratio
• To find the size you need, measure the widest cross-section circumference of your pack and then divide it by 2, which is the width of the tube you need. 
• Use hair dryer  or heat gun to evenly heat up the tube to shrink until it is tightly wrapped around the battery pack.
• Width: 7.9 inch (200mm) before shrinking
• Sizes Available:
• Small - 5" 
• Medium - 8" 
• Large - 12"

This is the best shrink tube we have found for protecting 18650 battery packs. Comes in 3 different widths and is very easy to work with.

Very durable and adds an extra level of impact resistant.

Use a heat gun or blow dryer to apply. 

For rectangles, take the two smallest dimensions, add them up and that is the size shrink you need. So for a 11x3x4" battery, it would be 3+4=7" needed (size small). Then get whatever length of that shrink you need, plus add a couple extra inches on either side. Probably best to double the length in case you mess up you have enough for a second try.

Q's 

1. Is the size measured flat or by diameter?
2. Is the size before shrinking or the final diameter?
3. How much does this shrink down?
4. Do I need a special heat gun to use this?
5. Are other colors available?

A's 

1. This large tubing is measured flat.

2. The size is the measured before shrinking. 

3. This tubing has a 2:1 shrink ratio.

4. No a normal hairdryer will do the job. We do not recommend using an open flame from a lighter or torch to avoid introducing excessive heat to the battery pack. 

5. At this time the tubing is only available in black.