This is a high quality second surface long Focal Length parabolic mirror is from the cosmetic section. The greater the "x" magnification factor the mirror has (ex. x4 or x8) the SHORTER THE FOCAL LENGTH. The x-factor does not equal more power for solar. Shorter focal lengths make objects appear larger when used for reflective imaging. The power is 100% determined by the optical quality and the size of the mirror. Concentrated solar "concentrates sunlight" it DOES NOT "amplify sunlight". This is 100% true for page magnifying Fresnel Lenses too. Longer focal lengths allow for greater flexibility of heat away from the mirrors surface. x factors of 4x or 8x are generally too short for reasonable solar applications.