Mono Monday, 20th Century Invention

According to Google, "The first Pop up toaster, invented by Charles Strite in 1921. Initially, Strite’s invention was only sold to restaurants. However, in 1926 the Waters-Genter Company utilized his idea in order to manufacture the electric pop-up toaster for commercial use."
So many choices for this challenge as almost everything we see on a daily basis is a 20th century invention. Except, my electric bicycle oddly enough which I discovered after I photographed it to death only to find out the first prototypes where developed in 1895! Who knew? So, back to the toaster.