It is the classic high voltage warning symbol in yellow and black contrast.

It is the chemical weapon warning symbol in yellow and black contrast.

It is the iconic radiation hazard warning symbol in yellow and black contrast.

It is the iconic biohazard warning symbol in yellow and black contrast.

It is sticker residue covering most of the area. The sticker residue has different sizes and dimension ratios.Some are squares and some are rectangular. It depends on the adhesive. Some stickers are more different to be removed. They left more residue on the surface.

It is an idea texture for putting sticker residue on walls and travel luggage.