<P> Standard mini lights are T13⁄4, indicating that they are a tube shape ​ ⁄ inches (5.5 mm) in diameter . Larger mini bulbs, which began appearing around 2004, are about twice this size, but are still very uncommon . Both types, along with most of the candle - shaped ones, are pinched - off at the tip rather than the base during manufacturing . Most contemporary miniature light bulbs have an internal shunt that is intended to activate when the bulb's filament burns out . The shunt closes the circuit across the bad filament, restoring continuity, which allows the rest of the string to remain lit . However, if one shunt fails to close properly, the whole string will fail to light . </P> <P> Other miniature types include globe - shaped "pearl" and smaller "button" lights, which are often painted in translucent or pearlescent colors . "Rice" lights are tiny, like a grain of rice, and can even have a subminiature base, if they are not already fixed permanently to the wires (on low - voltage sets). Rice lights are typically transparent, although colored variations do exist . They are intended to create tiny points of light, and are suitable for decorating miniature models, small wreaths, and other similar situations in which even "midget" T13⁄4 lights may be too large . </P> <P> LED lights, which are encased in solid plastic rather than a hollow glass bulb, may be molded into any shape . Because the LED casts light in only one direction, the most common way LED lights are designed, even "plain" sets having some sort of crystal pattern to create refraction . </P> <P> Many bargain brands have dome - shaped LEDs which focus the light so that it's sharply visible when viewed head - on, but almost invisible from a perpendicular direction . This has both advantages and disadvantages, depending on one's decorating needs . </P>

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