The TriLite MS21 is a compact DC strobe warning light with an auto-voltage design covering 12 to 48 volts. One part number runs across the range, so voltage is not something you order.
Two models cover the mounting choice. The MS21-M is magnetic and the MS21-P is permanent. Both carry six dome colors: amber, blue, clear, green, purple and red.
Output is 3 to 4 watts at 3.6 joules through a 360 degree Fresnel lens, firing 70 to 80 times a minute, under an unbreakable polycarbonate outer dome. At 4.5 inches high and 5.5 inches across, it fits where a full rotating beacon will not.

What is the TriLite MS21 DC strobe warning light?

The MS21 is a high-output DC strobe for signaling, safety and warning work, rated by TriLite for indoor or outdoor use. It discharges a short burst instead of holding a lamp on or sweeping a beam. The Fresnel lens carries that burst through 360 degrees so there is no blind side, and the polycarbonate outer dome is specified as unbreakable, which matters on equipment that spends its life near racking, loads and door frames.

What does auto-voltage 12-48V DC actually mean?

One unit works across the whole range instead of one unit per voltage. TriLite specifies the MS21 for 12 to 48 volt DC input, so the same light runs on a 12 volt service truck, a 24 volt tug and a 48 volt forklift. For a mixed fleet the saving is in the stores, not the spec. You hold one part number, and a light pulled off a machine going out of service fits the next one in without anyone checking a battery plate.

Magnetic or permanent mount: which MS21 do you need?

The MS21-M is magnetic, which means it goes on in seconds and moves between machines as work demands. The MS21-P is the permanent mount and wires into the supply, which suits a light that belongs to one machine or one structure. Magnetic leaves a cord in the open and wants clean flat steel under it. Permanent asks for installation time once, then stops needing attention.

What dome colors does the MS21 come in?

Six: amber, blue, clear, green, purple and red. Fleets running mixed equipment often use color to separate vehicle classes or operating states, and six options give you room to do that without repeating yourself. Amber stays the general warning default and clear gives the highest raw output. Color conventions vary by site and jurisdiction, so confirm your own requirement before standardizing.

MS21 or MS2: DC or AC?

The supply decides. The MS21 takes 12 to 48 volts DC, which puts it on vehicles, forklifts and battery equipment. The MS2 takes 110 VAC, which puts it on fixed points wired to building power. Output matches across the two at 3 to 4 watts and 3.6 joules, 70 to 80 flashes a minute, with the same six dome colors. The MS21 is also the shorter of the two at 4.5 inches against 6.5.

Strobe, flashing or rotating: what is the difference?

A strobe discharges a short burst. A flashing light switches a lamp on and off at a fixed rate. A rotating beacon turns a reflector, so the beam passes the observer once per revolution. On a vehicle the strobe's advantage is that it stays visible against daylight and under high-bay lighting. Rotating beacons show direction better. Flashing lights are the simplest of the three to keep running over a long service life.

Where is the MS21 used?

On DC equipment that moves: forklifts, tugs, yard trucks, sweepers, service vehicles and mobile material handling. The permanent version also covers fixed DC warning points where mains power is not available. Mount it high enough that the burst clears loads and racking, and keep the cord clear of mast components and pinch points. The low profile helps on machines working under low clearances.