Comparison : Item # C6500-3500-48-3.5, Nylon 6 FDA Natural
Item # C6500-3500-48-4, Nylon 6 FDA Natural
Item # C6500-3500-48-4.5, Nylon 6 FDA Natural
Item # C6500-3500-48-5, Nylon 6 FDA Natural
Item # C6500-3500-48-6, Nylon 6 FDA Natural