Streamlight TLR-3.

Streamlight TLR-3
Price: $135
Light source: C4 Power LED
Output: 90 lumens
Battery provided: Panasonic CR2 lithium
Activation: up/down rocker
Modes: momentary, constant-on
Attachment: coin-slot bolt; insert blocks for specific models, plus Picatinny, mate to rail slot
Pros: Relatively straightforward fitting; very compact
Cons: Requires tool/coin for tight fit; switch difficult to reach/operate
Testers' comments: We could not reach this one at all on the FNP, but even on the Springfield it was tough to activate the switch--which in our opinion has far too much resistance.

Blackhawk Xiphos

Blackhawk Xiphos
Price: $200
Light source: Cree XRE Led
Output: 90 lumens
Battery provided: Blackhawk CR123A lithium
Activation: in/out horizontal lever
Modes: constant-on, strobe
Attachment: adjustable camming lever with rail index lug
Pros: Easy attachment; simple operation
Cons: No dedicated momentary-on mode; light became hot with extended use
Testers' comments: We really liked the no-frills, horizontal switch--easy to reach and operate, and intuitive. Some flickering was noted during manual slide cycling, but it wasn't evident during firing.

SureFire X300.

SureFire X300
Price: $249
Light source: unspecified LED
Output: 110 lumens
Battery provided: SureFire SF123A lithium
Activation: up/down rocker
Modes: momentary, constant-on
Attachment: pull-down Picatinny and universal lever latches or supplied Rail Lock
Pros: Lever latch easy to swap out to fit to gun; bright output
Cons: Larger footprint may not fit all guns; resistance to activate constant-on
Testers' comments: Strong, even light made this the hands-down illumination winner, and the press-in momentary switch is natural and handy to operate.

Insight WX150.

Insight WX150
Price: $240
Light source: unspecified LED
Output: 150 lumens
Battery provided: Duracell 123 lithium
Activation: independent, ambidextrous levers
Modes: momentary, constant-on, strobe
Attachment: Slide Lock pull-down universal or Picatinny latch bar
Pros: Independent switches; mode options available for either hand
Cons: Accessing modes slightly complicated; can be difficult to reach on some guns
Testers' comments: We liked the ambi mode options, but it was easy to get confused when switching back and forth between them.

Testing Procedure. Lights were mounted on a Springfield XD Tactical 9mm and an FNH-USA FNP9, except for the SureFire, which was too large to fit on the FNP9. Lights were subjected to a base function test of 50 rounds of Black Hills 9mm 115-grain FMJ Factory Seconds. Following this segment, some flickering was noted in the Blackhawk unit when slide was sling-shot closed. Except for the SureFire, lights were then tested on both pistols for an additional 60 rounds of the same Black Hills ammo by two different testers. (The SureFire underwent the same number of rounds but just on the Springfield.) No failures were noted.