Lewmar Simpson Lawrence produces the CQR anchor in 16 sizes, in galvanized steel and stainless steel, and in weights ranging from 15 lbs. to 700 lbs.
U.K. physicist Geoffrey Ingram Taylor (wikipedia page here: G. I. Taylor) invented the plow anchor. In 1933 Taylor and two friends set up The Security Patent Anchor Company. Taylor tried to put the word "secure' on the anchor however he wasn't allowed to register this common word, and so he came up a compromise and called the anchor CQR instead. Taylor's U. S. Patent 1,974,933 awarded in 1934. Patent drawing below.
Taylor published an article in the 1934 April issue of Yachting Monthly where he explained his new design: Holding Power of Anchors
Manufacturer's website: Lewmar and link to the page on the CQR.