Presentation graphics are something that I have to try and keep my eye in with, this is a test piece with 128 pixel toolbar buttons. Its the type of interface you design for accountants, management and the like who are technical dills in IT terms. They most often have high end computer hardware available, (HDMI resolution on fast graphics cards) so you can happily make executables that are far bigger than will happily run on old hardware.
I definitely own the stop button, the other three are modified samples so they may not be available commercially unless you find the image owner and pay for it.