The Type-1 had eight adjustible settings, ranging from stun to heat through disruption to disintegration. The 23rd century type-1 in use in the 2260's incorporated a small flip-up sight, and was fired by a trigger on the bottom front of the unit. Several versions of the Type-2 Phaser incorporated a Type-1 Phaser into their design. A low power variant of the Type-1 was also available. This variant only had three settings, from light to heavy stun. (TNG reference: Star Trek: The Next Generation Technical Manual)