3 in 1 Pocket-Size Digital White Black Grey Balance Cards 18% Gray Card with Neck Strap for Digital Photography ( #: D1424 )

Features:
Includes three color calibrated reference cards.
It helps you get correct white balance, or color balance, allowing the camera to compensate for the illuminant color in a scene. 
For optimum color correction: the black card achieves truly deep blacks (RGB 16,16,15); the grey card displays superior spectral neutrality with measured values of 162, 162, 160; the white card has a tested RGB value of (220, 224, 223).
The neck strap with quick-release plastic buckle on the end, convenient for your use.


Specifications:
Item size: 85 * 54mm / 3.4 * 2.2in
Color: Black/White/Grey
Package weight: 34g / 1.21oz

Package List:
3 * Balance Cards 
1 * Neck Strap