Both trimmers are designed for nose and ear hair trimming, with the NT3650/16 also suitable for eyebrow trimming.

NT3650/16 comes with 2 fixed eyebrow combs (3mm and 5mm), while NT1650/16 does not have eyebrow comb attachments.

Both feature stainless steel blades and are washable for easy cleaning.

NT3650/16 has an ergonomic textured handle for better grip; NT1650/16 lacks this feature.

Both use one AA battery and require no oiling for maintenance.

NT3650/16 is waterproof and suitable for wet use like in the shower, while NT1650/16 is washable but has less information on full waterproof capability.

NT3650/16 includes a travel pouch; NT1650/16 does not.

NT1650/16 weighs approximately 139g, NT3650/16 is slightly bulkier but more feature-rich.

Both provide comfortable and safe trimming without pulling or cutting the skin.

NT3650/16 is a newer, more advanced model with additional grooming features and accessories.