We currently don't sell the Classic in 18 inches wide, but we do offer the Premium true dual density filter roll in 18" x 72", 18" x 12' and 18" x 24' here is the link if you want more information about this filter pad:

Premium True Dual Density Filter Roll - 18" by 72" by .75" to 1"

https://www.amazon.com/dp/B01AHHN5QG

Our Classic filter pad has more of an open weave to trap large particles while our premium dual density filter pads' top layer has an open fiber construction to trap larger particles while the bottom layer's dense fiber network Traps fine particles.