noise reduction wireless tour guide system

{"cid":"91171271","title":"Larger Lithium Battery Wireless Tour Guide System 150m Distance K8 Model","imgUrl":"https:\/\/img.chinax.com\/nimg\/83\/cb\/c0aa9d6548f82eff4407af145cd9-200x200-1.jpg","attrs":{"Price":"negotiation","Brand Name":"YingMi","Model Number":"K8","Minimum Order Quantity":"1pcs","Delivery Time":"3-7 days","Certification":"CE,RoHs","Place of Origin":"China","Payment Terms":"L\/C, T\/T, Western Union, MoneyGram","Supply Ability":"10000pcs one month","Packaging Details":"packed in carton box","Color":"Black","Working quantity":"50CH","Working distance":"More than 150m","Warranty":"2years","Frequency domain":"UHF","Frequency Response":"20Hz-3.4KHz","Dimensions":"118\u00d743\u00d714.5m","Place of origin":"China","Distortion factor":"<1%","Working current":"140mA"}}