Postcard Fresnel Lens

Postcard Fresnel Lens
Postcard fresnel lenses:Negative Focal Length Fresnel Lens Used As a Diverger.Positive Focal Length Fresnel Lens Used As a Conector.Positive Focal Length Fresnel Lens Used As a Collimator.
Postcard Fresnel Lens product offered by Hengwen Optics Components Co., Ltd.