Where can i get a 15 inch driver for the orbot?

[msc1917]

I have 19 inch velcro driver on the machine right now but what i dont love is the fact that the velcro driver extents past the bottom of the machine which is risky with resi. Id like to change it out for a 15. Know where i can get one? Not looking for a debate on driver sizes or techniques, just need to be pointed in the right direction. Thank you so much for your help guys.