The GoMotion Fusion is a fairly unique product: essentially it is a headlamp-like body suspended, between a pair of straps, that then attach to the straps of a backpack or vest. The lamp is powered by an external battery unit that can be placed in (or mounted on) the main backpack or vest body. The battery unit itself features a blinking red light for additional rear visibility. The chest-mounted light provides more than ample illumination, and the rear-mounted flashing red LED provides an additional level of visibility when running on roads. The Fusion is fairly easy to set up and use, and tended to stay put on backpack straps in testing. The height of the light was just about perfect for providing depth perception when used in conjunction with a headlamp. For runners who already have a favorite running pack or vest but want a body-mounted light, the Fusion is a convenient option. 

The primary limitation of the Fusion is that body-mounted lights do not follow the runner’s head movements. This was primarily a concern on trails when trying to scan ahead for turns and obstacles, and essentially forced running at much slower speeds. A secondary issue was that securing the Fusion pulled enough on the backpack straps to change (albeit slightly) the ride and feel of the pack. Mounting the lamp unit on elasticized straps could potentially remedy this issue. The battery unit was also awkward to mount externally on the rear of the pack. The battery unit is surrounded by a fabric shell that closes with Velcro. The Velcro can be threaded through straps on the pack for mounting, but it clearly wasn’t designed for this. 

The Fusion has two obvious sets of users. The first is runners who run-commute with a pack and either don’t want to use a headlamp or want to supplement a headlamp. The second is runners who are out on trails at night—think ultrarunners—and want a body-mounted light for additional illumination and depth perception. 

Comfort
The only comfort issue I encountered was when the battery unit was placed loosely in the back of the backpack and started to bounce around while running downhill. This was easily remedied by simply moving the unit to a different, more secure location and/or using its Velcro shell to attach it to part of the pack. Otherwise the Fusion was a little more comfortable than a typical headlamp, if for no other reason because it didn’t require straps around the head. 

Brightness
The Fusion has a quoted maximum output of 100 lumens. This is fairly typical and more than adequate for enhancing visibility and illuminating the area in front of the runner. 

Ease of Use
The Fusion has three controls. The first is a button that cycles through the different illumination modes, which are really just three brightness levels. The second is a button that turns the light on or off— this is a bit more convenient than a single button that must be cycled through all modes to switch the light off. The third controls the beam width. This allows switching between spot-like and area-like illumination modes, but the actual mechanism was somewhat stiff, and required a level of fine-motor-control that made it difficult to adjust while running—as opposed to a button which just cycles through various beam width settings. Mounting the light to a backpack was straightforward, and the overall system was quite easy to adjust. It also can be left mounted to the pack with one end of the lamp unit attached. 

Features
Although it mounts to the body, the feature set of the Fusion is not all that different from a headlamp. There is no red LED mode, but the light has a wider range of adjustability than is typically seen on headlamps. The best feature of the Fusion is the rear-mounted red light. 

Run time 
The Fusion has a quoted runtime of 50+ hours on the lowest power setting. So the runtime-to-weight ratio is considerably lower than what a headlamp offers. However no issues were encountered with battery life during testing.