The red telephone box, a public telephone kiosk designed by Sir Giles Gilbert Scott, was a once familiar sight on the streets of the United Kingdom. It has all but disappeared in recent years, replaced by a number of different designs. The few kiosks that remain have not been replaced because they are regarded as being of special architectural and historical interest. The first standard public telephone kiosk introduced by the United Kingdom Post Office was produced by Somerville S. Company in 1920 and was designated K1 (Kiosk no. 1). This design was not of the same family OS the familiar red telephone boxes. The red telephone box was the result of a competition in 1924 to design a new grander kiosk. The competition attracted designs from a number of noted architects. The Fine Arts Commission judged the competition and selected the design submitted by Sir Giles Gilbert Scott as the winner. The Post Office made a request that the material used for the design be changed from mild steel to cast iron, and that a slight modification is made to the door; after these changes, the design was designated K2 from 1927 K2 was mainly deployed in and around London. K3 designed in 1930. again by Gilbert Scott was similar to K2 but was constructed from concrete and intended for rural areas. K4 (designed by the Post Office Engineering Department and proposed in 1923) incorporated a machine for buying postage stamps on the exterior. Only 50 kiosks of this design were built. 1(5 was a plywood construction introduced in 1934 and designed to be assembled and dismantled and used at exhibitions. In 1935 K6 was designed to commemorate the silver jubilee of King George V K6 was the first standard telephone kiosk to be used throughout the country.