Good surface cleaners that won't scratch aircraft windows are hard to fine. Prist® will not harm acrylic, stretched acrylic, polycarbonate, glass and coated glass windscreens. It also works on metal and vinyl without harming painted surfaces. It breaks down and removes stubborn grease and dissolves organic residue with a minimum of scrubbing. It also contains an anti-static compound that prevents the buildup of static charge, which can attract airborne particles that can scratch surfaces while cleaning. GROUND SHIPPING ONLY. CANNOT BE SHIPPED BY AIR OR OVERSEAS.