This bulb is made by Philips. It is frosted on the inside and comes with an integrated electronic dimmer chip. The slogan on the box reads "The light that works like a dimmer switch". Below are the instructions printed on its box:
Simply place into any regular lamp or wall fixture. When first turned on, the highest level will appear. To change to lower levels, simply turn the light switch off and on again. If the bulb stays unlit for any ten minute period, the micro-chip will automatically reset itself to the highest level. DO NOT USE WITH DIMMER SWITCHES.