Description: Material:MDF Size: 11.8inch Color:black Quantity:1 x math clock Package included:1 x math clock Note: ​Alkaline batteries are not suggested.Uses 1 AA carborn battery - not included(alkaline batteries may leads to the clock's inaccuracy). The size of the manual measurement may have some error, it is within the range of ±1 cm, the actual size shall be subject to the actual object. Due to different lighting and shooting conditions, the color of the image may differ from the actual product. Please refer to the actual product. PERFECT SIZE: 11.8" wall clock.Printed on fiberboard face,not real wood (MDF) ,no frame, no cover.The perfect wall clock for an office, classroom, bedroom, bathroom and any room in your home. GO WITH EVERYTHING DESIGN: Black and white color scheme makes the clock look like a chalkboard and will complement any color. A UNIQUE WAY TO TRACK THE HOURS: Instead of Roman numerals or traditional numbers, this wall clock has a different equation at each demarcation. GREAT GIFT IDEA: Give one of these wall clocks to a math teacher, engineer, mathematician or anyone who just loves numbers. NON-TICKING: Precise quartz movements guarantee accurate time.Enjoy a quiet environment!