The Eldar have a grasp of many forms of technology which far surpasses that of other races, and it is this knowledge that allows them to make wide use of plasma missiles. Eldar missile launchers may fire krak or plasma missiles, with the profiles given below. A squad that takes casualties from a plasma missile must test for pinning (page 58 of the Warhammer 40,000 rules).
Krak Rng: 48" S: 8 AP: 3 Hvy 1 Plas. Rng: 48" S: 4 AP: 4 Hvy 1, blast