Lenovo X3 is IPX45 waterproof, Built-in Loudspeaker, Not a Bone Conduction Headphone. Lenovo X3Pro is IPX56 waterproof, Built-in Bluetooth 5.3, Bone Conduction Headphone. Lenovo X4 is IPX56 waterproof, cannot be used for swimming, no storage, Bone Conduction Headphone.
