This product is indeed the "CV 300 Plus" cartridge. The product photo is very awkward because the product name is hidden right behind the green lid. An additional photo from above down on the lid would be appropriate here.

It fits quote:''Campingaz CV series cartridges''. see description by product.
CV..Plus is supposedly the new range designation of their products (old just CV). I cannot say 100% whether this is really the case.