The Julbo Optical Clip is a plastic insert for goggles that the user can have fitted with optical lenses by their optician.
It has plastic retaining springs that hold it in position and will fit most goggles, not just Julbo ones, and they do not need to be special OTG (Over the Glasses) goggles.
This is a one piece device which Julbo says is for L to XXL goggles, ie not children's sizes.
Lens Size: 51mm.
Lens Height: 43mm.
Bridge Distance: 15mm.
Base: 6.