Made in Canada.

Muddy black plate, Side O-Getter.

Nos in original box.

Made in USA by RCA.
Gray, black, muddy black plate.
Bottom, side, top getter.
Nice tube.
All are nos. Some in box, some no box.

Made in USA by RCA.
Muddy black plate. top-side getter.
Good tube.

Nos in original box.

Made in USA by Sylvania. 

Glass octal type used in power supply of radio equipment having large dc requirements.
Requires octal socket. Except for basing, it is identical to 5U4G.
Nos in original box.

Made in G.Britain by Mullard. 

Best version of U52 type.