Hi-float

Available in 3 sizes 

Ultra Hi-Float is an aqueous solution containing a special water-soluble plastic. 

It dries inside the latex balloon to form a barrier coating that helps hold the helium. 

With Ultra Hi-Float balloon flight extender, you can increase the float time of latex balloons by up to 25 times. 

Instructions on how to use can be found at www.hi-float.com