This is a very cool sign!  Hercules Tires started in 1952 and still operates today.  They used this slogan 'Best Rubber on the Road' during the 1950s-1970s, which very much matches up with the style of this sign.  
 
Measurements 49 inches long x 9 inches tall.  
 
The maker's mark is NPI, Neon Products International, which is a well known vintage sign maker.  
 
We upgraded the interior lighting to LED, so there is a 110v plug and an on/off switch on it that powers the sign.
 
The can is metal, and there are two predrilled mounting holes on the back for hanging, or you can display with the two metal hooks on the top.
 
Condition notes:  No breaks in the sign face, there are minor scratches, minor paint flaws, you can see these especially when the sign is lit and up close, I added a video.  The can also shows age, paint wear and minor flaws.  Everything works as expected.