ApcoFlex ability of easy fabrication and close adhesion to duct makes it an excellent choice for any shape of duct insulation,It can be used Indoor and outdoor installation.It have applied vapor.............. barrier for front side surface and it is faced with embossed reinforced Aluminum foil,laminated by heat,Aluminum surface is treated and protected by special coat to protect surface against weather conditions and prevents build up of bacteria contamination, fungus and due formation. Recommend thickness and thermal calculation are available on request. <