For Keypad, we have 4 versions available for you to suit your job and budget. Material: ABS plastics.Dimensions: 137 × 46.6 × 22mm (L×W×H).Weight: 110g (inclusive of battery).Display Specification: 128 *48 matrix LCD.Apparent Area: 35.81 x 14.37mm. Rugged ABS plastic shell, firm & durable, credit-card size Dimensions: 92mm × 54mm × 8mm ( L x W x H) Each keypad has a unique ID number between 1-9999. The ID number of each keypad can be changed through our software Rugged ABS plastic shell, firm & durable, credit-card sizeDimensions: 92mm × 54mm × 8mm ( L x W x H)Each keypad has a unique ID number between 1-9999.The ID number of each keypad can be changed through our software Dimensions: 82 x 41 x 10mm(L×W×H);Weight: 28g (inclusive of battery).TN Display LCD, 13.6 x 14.5mm;Display: English, Number, Icon;Status icons to indicate signal strength, communication status and battery level. For Base Station Receivers we have 3 versions available for you to suit your job and budget. Dimensions: 137mm×125mm×25mm (L×W×H).Material: ABS plastics.Weight: 215gIndicator Light 3 indication lights: link light, two data lights.Status light flashes slowly: connect base station to computer successfully;Status light flashes fast: connect base station to application software successfully; Material: ABS plasticsDimensions: 137mm×125mm×25mm (L×W×H)Weight: 215g (including antenna)Each base station has a unique 5 byte serial number (11 bits in all).Each base station has a unique 4 byte match code.1 power port: external power supply for NET connection. Rugged ABS plastic shellDimensions: 91mm ×31mm × 12mm (L x W x H)Weight :24 g2 LED status indication lights - One for indicating the communication status between USB and PC - One for indicating the communication status between base station and keypads An audience response Plug-in for Windows PowerPoint ,Support multiple choice, ranking, voting, rating.Support PPT issue editingSupport Chinese/English/Japanese/Spanish/German/French/Thai