Unity Tactical SPARK Blinking Marker Light All Polymer Construction Velcro Backer Matte Finish On/Blink/Off Infrared. A completely sealed unit SPARK is waterproof for function in a multitude of austere environments. It attaches to surfaces with a hook and loop backing. When paired with the SPARK CAGE it can weave onto webbing or snap onto metal surfaces with magnets. Pressing the center of the silicone housing SPARK will cycle through its output functions. The constant feature is good for low light training while the blink output acts as an emergency strobe beacon. The Spark CAGE increases the versatility of the popular SPARK Marking Light. Molded from impact resistant polymer it secures a single SPARK via press-fit. All four sides feature a split pass-through for standard 1 webbing. Integral rare earth magnets allow it to attach to most metal surfaces. Features of Unity Tactical SPARK Marking Light : 200+ Hour Run Time Package Contents: Unity Tactical SPARK Marking Light Unity Tactical SPK-IV1: Marker Light On/Blink/Off Infrared