This is a 1-mil polyimide film backed tape with acrylic adhesive. It's acrylic pressure-sensitive adhesive allows it to be used at 311°F (155°C), and it is UL 510 Flame Retardant.
Tape 1205 is used for high temperature electrical applications in which a tough thin insulating material is required for wrapping coils, transformers, capacitors, wire harnesses and for anchoring leads/terminal boards. It is also used in printed circuit board assembly as a wave solder masking tape.