Enclosure: Lightweight, compact, "credit card" sized case. Rugged ABS plastic construction. Dimensions: 94mm L51.5mm W7mm H. Weight: 25g (without batteries). 3130mm LCD display Color: Black. (Other colors available while minimum order quantity required) Output: 16 keys Power :by one coin cell CR2032 Lithium Batteries Software: 100% integrated into Microsoft PowerPoint, easy to edit and follow your habits; More intuitively display of your topic. Supported Functions: Single/Multiple Choices\Grading\Scoring\Right/Wrong\ Numeric question\Rush Answer...(contact us for more functions) Voting results displayed in real-time, report can be output and preserved permanently Diversified report forms help you analyze the research project from multiple perspectives Offer a variety of question types, highly interactive and make lively class. Two-side response, distance could up to 100m. Powerful signal and no direction limited. 50pcs in one carry bag.