The type 8 phaser is a ship-mounted phaser emitter.

In 2293, the phasers of the Excelsior-class USS Enterprise-B were listed as type 8 phaser emitters in the bridge master systems display. (Star Trek Generations production art)

In 2370, the Cardassian warship Vetar came under attack by a fleet of small Maquis attack fighters armed with photon torpedoes and type 8 phasers, which inflicted heavy damage to the Vetar. Gul Evek accused the Federation of supplying these supposed civilians with the weaponry, but Captain Jean-Luc Picard assured Evek that however they got them, it was through unofficial channels. (TNG: "Preemptive Strike")

Phaser technology
Tools: phaser bore • phaser drill
Weapons: Automatic bridge defense system • Bajoran phaser • Bajoran phaser rifle • compression phaser rifle • Ferengi phaser • Galor-class phaser bank • hand phaser • Kzinti phaser • particle phaser • phaser array • phaser bank • phaser cannon • phaser emitter • phaser pulse • phaser type-1 • phaser type-2 • phaser type-3 • phaser type-4 • phaser type-8 • plasma phaser • Regalian phaser rifle • regenerative phaser
Other: phaser adapter • phaser coil • phaser coolant • phaser coupling • phaser range • phaser relay • phaser room • phaser sweep