The Colt House Revolver (also called, in its alternate 4-round capacity model, the Cloverleaf) was one of the first metallic cartridge rear-loading revolvers to be produced by the Colt's Patent Fire Arms Manufacturing Company, back in 1871. The same year, Colt's also patented the Colt Open Top, another metallic cartridge rear-loader, but in fact the Open Top production didn't start until 1872, although a pocket version of the Open Top, a completely different design, went on sales as of 1871, the Colt Open Top Pocket Model Revolver.