I've used the CBconcept 12 volt version of these bulbs in my landscape lighting for 3 years and they've been great, so when I installed some 'puck' lights under my cabinets I figured I'd try these. The fit was fine, hard to install in lights while contorted upside down on the counter, but hey...that's why I do yoga. :) Key thing is, don't touch the bulbs with your bare fingers at any time, or they'll burn out in a week. Either use the plastic they come in as a gripper, or use rubbing alcohol to wipe them off.