The Enders Speed razor was developed around 1930. It was sold by the Enders Razor Company. One of main selling points they tried to get across was the fact that this was a “one piece razor”. You didn't have to (and couldn't) take the razor apart to change blades. This was achieved by using special, proprietary blades. Here is a link to a page where there is lots of info on the razor and the blades.
It is mostly a collectable, but there is a fairly simple way to still use it with modern blades, you need to do a small mod on an old blade and then use it to keep the modern blade snug and fit. Here is a video on the process.
This razor weighs 28 grams and stands 100 mm high. The razor is in great shape and comes with one original blade.