Right out of the box, the SWITCH60 feels impressive, like a Cadillac version of a regular bulb. It has the globed shape of the 60-watts I used to buy before switching to CFLs, but it's way, way heavier -- the weight is the first indication that it's a piece of technology, not just a thin piece of glass you screw into a lamp and forget. On my kitchen scale, it weighed in at 9.8 ounces, about as much as a typical volleyball.
The weight is behind this bulb's secret -- it's full of liquid silicone, which dissipates heat from the 10 LEDs (12 LEDs for the 100-watt version). Warmer silicone moves toward the glass exterior, where heat dissipates into the air; as it cools, the silicone drops back toward the bulb's heart. Think of a lava lamp; this works basically the same way, said Dave Horn, chief technology officer at SWITCH. You just can't see the gloopy circulation.