I am trying to register a mark that was refused for ‘likelihood of confusion’ with a registered mark I already own. How do I respond?

I used the exact same description of goods on both marks since they are identical products. Each mark was created to signify different weight limitations, i.e.
The Mark “A” device has a capacity of 30-60 lbs.
The Mark “B” device has a capacity of 60-120 lbs. (and can be made custom as well).
Customers would associate Mark A as light to medium weight, and Mark B would be medium to heavy weight or could be custom made, (even heavier).
~ Florida

You can claim ownership of a prior registration by amending your trademark application. You may wish to review TMEP section 1201 et seq. This may overcome the Examiner’s refusal.

I recommend consulting with your attorney prior to making the amendment. If you are representing yourself, you may wish to interview the Examiner prior to entering the amendment.