have be able to use mine for about 40 hour . after that it fail to respond to any input from any source . contact Benq and they say there be nothing they could do but send it in for repair since they have be have problem with these unit . send it in and get it back . it work once during a test preparation for a presentation but once again fail to acknowledge any input when turn on the next day during the actual presentation . contact Benq and they say I could have it repair -lrb- be not repair last time -rrb- or receive a refurbish unit -lrb- someone else 's problem -rrb- . so be work on my third round , maybe I 'll be lucky this time . it will be my last Benq product . I can not recommend the product or company .