Compare with others, the HLKGO-USBE advantages as following: 1.Totally get rid of the main unit limited. 2.Easy to usage . 3.Portable and compact . 4.Only plug in, then the laser will output automatically. 5.It can be powered by the portable power bank, adapter or computer. 6.The National patent protected technology .?Use method? 1.Connect the ear cavity wire to the power supply 2.Insert the ear applicator the the ear 3.Start 4.It does not require a host, directly connected to the power supply, convenient to carry. ?Without Side Effects?Positive clinical trail proved, CFDA and CE certified. ?Small Lightweight?The red light ear therapy device comes with portable bag,smaller size can be carried in the bag at any time. ?Hands-free Portable?There is an adjustable buckle design on the main line, which can be used for treatment while walking without falling off.It does not require a host, directly connected to the power supply.