1) No effect to your Macbook and easy installation.<br />2) Protect your laptop against dust and moisture.<br /><br />3) Material: The case is plastic hard case (include top case and bottom case)<br /><br /><br />About Model Number:<br /><br />Please kindly check the model of your Macbook before purchasing!<br /><br />Note: If you're not sure the model・ please kindly check the back of your macbook・ you could see the model (Axxxx) printed there.<br /><br />A. Pro 13'' A1278 (Have CD-ROM・2009-2012)t<br />B. Retina Pro 13'' A1425 and A1502 NO CDROM<br /><br />C. Air 13 ''<br />D. Air 11 ''<br /><br />E. Pro 15'' A1286 (Have CD-ROM・2009-2012)t<br />F. Retina Pro 15'' A1398 NO CDROM<br /><br />G.Macbook 12 ''   <br />H. Pro 13 A1706 A1708<br />I. Pro 15 A1707<br />