The LA-DC58L Conversion Lens Adapter for PowerShot G15 & G16 Digital Cameras ; from Canon screws onto the face of the Canon G15 or G16 ;around the lens and is required in order to attach optional converter lenses and accessories to the camera. Without accessories attached, it can also be used to provide protection for the lens from accidental impact. Accessories including the TC-DC58E Tele-Converter, the MP-14EX Macro Ring Lite and the MT-24EX Macro Twin Lite connect to this all metal conversion adapter.