2N2175 semiconductor manufactured by Sylvania, listed as 2N2175 (circa 1979).

2N2173 semiconductor manufactured by Sylvania, listed as 2N2173 (circa 1979).

2N2172 semiconductor manufactured by Sylvania, listed as 2N2172 (circa 1979).

2N2171 semiconductor manufactured by Sylvania, listed as 2N2171 (circa 1979).

2N2170 semiconductor manufactured by Sylvania, listed as 2N2170 (circa 1979).

2N2169 semiconductor manufactured by Sylvania, listed as 2N2169 (circa 1979).

2N2168 semiconductor manufactured by Sylvania, listed as 2N2168 (circa 1979).

2N2167 semiconductor manufactured by Sylvania, listed as 2N2167 (circa 1979).

2N2166 semiconductor manufactured by Sylvania, listed as 2N2166 (circa 1979).

2N2165 semiconductor manufactured by Sylvania, listed as 2N2165 (circa 1979).

2N2164 semiconductor manufactured by Sylvania, listed as 2N2164 (circa 1979).

2N2163 semiconductor manufactured by Sylvania, listed as 2N2163 (circa 1979).

2N2162 semiconductor manufactured by Sylvania, listed as 2N2162 (circa 1979).

2N2161 semiconductor manufactured by Sylvania, listed as 2N2161 (circa 1979).

2N2160 semiconductor manufactured by Sylvania, listed as 2N2160 (circa 1979).

2N2159A semiconductor manufactured by Sylvania, listed as 2N2159A (circa 1979).

2N2159 semiconductor manufactured by Sylvania, listed as 2N2159 (circa 1979).

2N2158A semiconductor manufactured by Sylvania, listed as 2N2158A (circa 1979).

2N2158 semiconductor manufactured by Sylvania, listed as 2N2158 (circa 1979).

2N2157A semiconductor manufactured by Sylvania, listed as 2N2157A (circa 1979).