If you are looking to replace an existing incandescent bulb then one of these LEDs will be a good fit for you. You can't tell the difference when they are lit up and they use so much less energy. If you are looking to replace a 25W incandescent lamp, select something close to a 2W LED. If you are looking to replace a 40W incandescent lamp, select something close to a 3.5W LED. If you are looking to replace a 60W incandescent lamp, select something close to a 4.5W LED. Not all LEDs are dimmable. If you really need your lamp to be dimmable ensure you select a variant that states the word  'dimmable.'  The lowest wattage dimmable LEDs we have are 3.5W. If you are concerned that you have a dimmer switch in place and the LED to be used is not dimmable, we recommend you ask your electrician to either: a) replace the switch, or b) even neater, replace the dimmer module to an 'on/off' only version. A module is the bit behind the dimmer knob powering the lamp(s) and it is quite easy to change. If you find that your dimmable leds still 'flicker' when dimmed, you may need to ask your electrician to replace the module with a trailing edge version