Adhesive Mastic Beading Butyl Tape Applications: Automotive/Marine/Renewable Energy The Co-Star Butyl Mastic Beading is an extremely, strong, versatile and flexible sealant. It has excellent adhesive properties to most substrates and has excellent UV & geing properties. Excellent UV & ageing resistance Good adhesion to most substrates Permanently Flexible Seal Easy & quick to use 5mm (width) x 5mm (thickness) x 12m roll