The ProTac 2L-X features an aircraft-aluminum body with a hard-anodized finish, a tempered-glass lens and O-ring seals. The total length of the light is 5.14 inches long, with a head diameter of 1.06 inches and a body diameter of .94 inches. The total weight, with two CR123 batteries, is 3.9 ounces. An optional lithium-ion rechargeable battery pushes the weight to 4.4 ounces. The light operates with C4 LED technology, which features a 50,000-hour lifetime and is impervious to shock.
The light features three separate settings: high, low and strobe. The high setting features an output of 500 lumens, while the low setting features an output of 40 lumens. Using CR123 batteries, the high setting features a total run time of 2.45 hours, while the low setting will run for 30 hours. The strobe function operates for a total of 3.25 hours.
Streamlight offers an optional 18650 rechargeable battery that increases total run time, but it also adds 1.5 ounces to the total weight of the flashlight. With the rechargeable battery, the high setting features a total run time of 3.25 hours, while the low setting features a run time of 30 hours. The strobe function has a total run time of 4.5 hours.
The ProTac 2L-X operates using Streamlight's trademarked Ten-Tap programmable switch. Simply depress the tailcap to turn the light on high. To keep the light in its 500-lumen setting, depress the tailcap until it clicks. To reach the strobe setting, depress the tailcap slightly twice within 0.4 seconds. Depressing the tailcap fully after reaching strobe will allow the strobe mode to remain on without depressing the tailcap. The same procedure is followed for the low mode, except that the tailcap must be depressed slightly 3 times within 0.4 seconds to reach the low setting.
The programmable switch is available with three separate user-selectable programs. The first program, available as a factory default, is high/strobe/low. The other two programs are high only and low/high.
The ProTac 2L-X is rated IPX7 waterproof up to 1 meter for a total of 30 minutes. The light has also been rated impact-resistant for drops up to 2 meters. Other features include an anti-roll facecap, a removable pocket clip and a crenelated bezel for use as a striking implement in personal defense.