Model SX-M823 Size:8.54*5.1*3.01cm Weight:78.2g Bran-new high speed RF wireless technologoy,offer the same function as wire connector,no wire connector needed,Combine with high resolution and frame,even 800DPI,tha you can have the sense of the lightest operation;between 2 meters,you can get a good effect even on numerous desks,It's a ideal combinction together with optical definition and advanced wireless technology. Entire support USB port and PS/2 port,wireless tracking,ideal for mobile users;sliding on any surface(except glass)(. Product Features Radio frequency 27MHz,enjoy your freely wireless space It has 256 ID code,there is no interf-erence enen may mice being used at the same time. Automantically save power sleeping functions,batterbeprolonged Mechanical Performance Body Material:ABS/PC Switch:60±15gf Key Operation:60±15gf Switch life:1000,000