A light-emitting device having a higher aperture ratio in pixels than that of the prior art. The inspection system includes a laser focus module, a microscope objective module, an image pick-up module, and a process module. The projections may be placed over the rim of a propeller hub, rim of an exhaust port, or the lower portion of the trailing edge of the propeller blade generally close to the hub. Arranged adjacent to an inner circumferential surface of the readily elastically deformable layer is an inner layer that is stiffer than the readily elastically deformable layer. The ladder attachment has an illuminating portion providing light which can be utilized to identify the location of a ladder in, for example, an emergency situation.