About delivery, I ordered at 17:00 I received the package the next morning at 11:00 am with the optical Sigma 35mm f 1 / 1.4 DG HSM ART: a "super express" service! The USB docking station seems to me an essential complement to any objective in need and allows more precise calibration (opening requires) that the internal correction for Canon bodies associated an upgrade of the internal software. Nothing to add, it's perfect.