Feature: 1.Wireless table buttons can put on the table, also can hang on the wall. 2. Different style and color for your selection 3. One host board can match with 30 pcs table buttons. In the same area can connect more than one host board. 4. Wireless call buttons all can mix and match with SK-300 ( Receiver) 5. OEM, ODM acceptable Two kindof Receiver SK-300SK-302 LED DisplayFrequency:433Mhz Frequency:433MhzCoverage: 500 MCoverage: 500MCode Format: ManchesterCode Format:ManchesterCan work with 30 pcs transmitterCan work with 99 pcs transmitter, Show number in three different color reprent three kind of service: Service,Drink, BillOperating Temperature:-10C-70COperating Temperature:-10C-70C Four kind of Transmitter SK-311SK-312SK-313SK-3151 key (Call)3 key(Serice,Drink,Bill)1 key (Call)2 key(Call, Cancel)Brown ColorBrown ColorWhite with Green or OrangeBrownFrequency Stability:99.5%Frequency Stability:99.5%Frequency Stability:99.5%Frequency Stability:99.5%Battery:12VBattery:12VBattery:12VBattery:12V Receiver Photos SK-302 SK-300 Transmitter Photos SK-311SK-312 SK-313 SK-315