JJC GC-1 2-In-1 8" x 10" Digital White Balance & Gray Card, 2 Packs 8" x 10" White Balance / Gray Card x 2Packs Accurate color balance tool Work with any film or digital camera Can be used in pre-production or post-processing Gray Side: 18% reflectance; White Size: 90% reflectance 8" x 10" White Balance / Gray Card x 2Pack^ Accurate color balance tool^ Work with any film or digital camera^ Can be used in pre-production or post-processing^ Gray Side: 18% reflectance; White Size: 90% reflectance