DCS-7050S-52, DCS-7050S-64, DCS-7050T-52, DCS-7050T-64, DCS-7050T-36 = 4.18.x max
7050QX (or any X switch with 2gb flash, the latest is 2GB-4.24.x)
7150S and 7150SC 4.23.x (2GB only I believe) (4.23.x is EOL FOR 7150 on Dec 2023)
7050X-X2 (includes like SX SX2 QX QX2 TX2 TX etc) with 4G...