Black 2:1 single wall tubing shrinks to .25 in (6.4 mm)  Crossland Elastomer.  .5 (12.7mm ) inner diameter Flame Retardant.  -75 tob150 degrees Celsius. 

I have 40 rolls and each roll has 150 feet. This sells on the TE Connectivity website for $5.36 per Foot. I ended up having way to much over stock. 

Price is per roll. My price is less than half retail.