Will this tube, your 20x 1.25 replace my 20x1.5 tube?
This tube might be too skinny to replace your 1.5" wide tube. We do have a couple 1.5" wide tube options for your consideration - a heavy-duty tube, item K92-1826, or a standard tube, item K92-1737. Here are the links to those tubes:
Heavy Duty Tube:
https://www.monsterscooterparts.com/20-x1-50-1-95-heavy-duty-thorn-resistant-bicycle-inner-tube-with-straight-schrader-valve.html
Standard Tube:
https://www.monsterscooterparts.com/20x1-35-1-50-inner-tube-straight-valve-sunlite.html