The 302, or H mount telephone was the first telephone to have all the electronics housed in one unit; no more subsets. It was manufactured in large amounts from 1937 to 1958 replacing the old D1 style as the workhorse telephone. In total, over 25 million sets were manufactured. 302 originally used metal housings but were gradually switched to plastic in the early 40’s, partially due to war metal needs. Most 302’s were black, however special order color sets were available in the late 40’s and early 50’s.