The Preon Kit comes with a Preon head, Preon I body, Preon II body, clicky tailswitch, and a flat tailswitch. The Preon head is interchangeable between the bodies with light outputs dependent on the body (and, thus, number of batteries) that is attached. The head will also work with both tailcaps - the clicky allows you to control it with the button, whereas the flat tailcap turns the Preon into a "twisty" light just like the Preon 1.

Preon 1 Specifications

LED: CREE XP-G R5
Max Output: 70 Out-the-front (OTF) lumens
Material: Type-III Hard-anodized Aircraft-grade Aluminum
Lens: Optical-grade glass lens with anti-reflective coating on both sides
Battery: One AAA, included (see voltage range to select acceptable batteries for this light)
Operating Voltage Range: 0.9V-3.0V
Seven Output Modes:

Low: 1.8 OTF Lumens, 23 hours
Medium: 8.5 OTF Lumens, 6 hours
High: 70 OTF Lumens, 0.8 hours
Strobe 1.6 hours
SOS 2.4 hours
Beacon (Hi) 8 hours
Beacon (Lo) 40 hours

* Dimensions:

Length: 2.95 inches
Diameter: 0.55 inches
Weight: 0.5 ounces

Waterproof: IPX-8 Rating

Preon 2 Specifications

LED: CREE XP-G R5
Max Output: 160 Out-the-front (OTF) lumens
Material: Type-III Hard-Anodized Aircraft-grade Aluminum
Lens: Optical-grade glass lens with anti-reflective coating on both sides
Battery: Two AAA, included (see voltage range to select acceptable batteries for this light)
Operating Voltage Range: 0.9V-3.0V
Seven Output Modes:

Low: 2.2 OTF Lumens, 23 hours
Medium: 22 OTF Lumens, 6 hours
High: 160 OTF Lumens, 0.8 hours
Strobe
SOS
Beacon (Hi)
Beacon (Lo)

Dimensions:

Length: 5.05 inches
Diameter: 0.55 inches
Weight: 0.88 ounces

Waterproof: IPX-8 Rating

Included Accessories

Removable clip
Ring for keychain attachment