Allowing only numbers to be entered in the Other field of a Check Box

I have a need to only allow a number to be entered in the other category.  I do not want to allow customers to enter text.  Numbers only.  Is there a way to do that? 

We cannot limit the Other option of a Check Box field to accept only numeric entry, but we can achieve such a requirement by building our own "Other" option instead. We can do this by adding one more Number field to your form, and applying a show/hide conditional rule on it.

Here is how to achieve it, described in steps.

Step 1, adding a Number field to the form, and naming it "Other" or "Other Apparel Product". We will use this to get your "other" value, and since it is a number field, it will only accept numbers:

Step 2, access the settings of the Check Box field, by clicking on its gear-shaped icon (1):

Once it opens, switch to the Options tab (2), remove the custom Other option (3), and add an "Other" option among the regular options in your Check Box field:

Step 3, we finally set up 1 show conditional rule to show our Number field, if Other is selected in the Check Box:

https://www.jotform.com/help/57-Smart-Forms-Using-Conditional-Logic

Please try it out, and if you need any further assistance, please let us know.