The K40 is a POS that failed to jam a single laser gun used by police.
If you want the best radar/laser detector, get a Valentine One.
http://www.guysoflidar.com/march-2007/radar-detector-test.html
Spreadsheet of the radar/laser detector results:
http://home.comcast.net/~ccaeric6/GOL_averages_MB5.htm
If you want the best laser jammer, get the AL, LPP, or the soon to be released in the U.S. Laser Interceptor.
http://www.guysoflidar.com/march-2007/laser-jammer-test.html
AL:
http://www.antilaser.info/
LPP:
http://www.laserprotector.us/
Laser Interceptor:
http://www.laser-interceptor.com/index.html