13 volts per bulb) but not significantly reducing the light output of the bulbs. Large C7½ and C9¼ bulbs typically come in sets of 25, though bubble lights come in sets of seven, and some non-holiday sets come in ten or twelve. Sockets are usually spaced about one foot (30 cm) apart, and are clamped to the wire with an integrated insulation-piercing connector. Some older parallel sets had 15 bulbs, as do some of the newer globe sets manufactured today. Both of these bulbs are designed to run on 120 volts AC and the light sets that use them are wired in parallel. Miniature lights first came in sets of 35 (3.5 volts per bulb), and sometimes smaller sets of 20 (6 volts per bulb). For a short time, these early miniature lights were manufactured using E5 screw bases, rather than the current wedge base and were called "Italian lights". Sets of ten (12 volts per bulb) were made for very small trees, but are quite hot, and are now usually used for tree toppers only. This number is convenient for stars, which have a total of ten points (five outward and five inward), and often have another light in the middle, occasionally on both sides. Incandescent miniatures now usually come in sets of 50 or 100 (which contains two circuits of 50) 2.5 V 170 mA bulbs, though decorative sets with larger bulbs (C6 or pearl style) typically come in sets of 35 or 70. Several "extra-bright" sets also use 70 or 105 bulbs, keeping the per-bulb voltage at 3.5 instead of 2.5. LED sets can vary greatly. Common is a set of 60 (2 volts per bulb), but white LED sets use two circuits of 30 (4 volts per bulb). Multicolor sets may have special wiring, because red and yellow require less voltage than the newer blue-based ones (blue, emerald green and fluorescent white), but typically come in sets with a multiple of 35. Battery-powered sets typically come in 10 or 12, and can use standard 2.5 to 3.5-volt bulbs because they run two batteries, totaling three volts or less. LEDs are becoming increasingly common as they greatly prolong battery life, but because they also last longer they are often soldered directly to the wires, making up for some of the increased cost of the newer LEDs. "Rice lights" are often made this way as well, and likewise