>>239でいいんだと思う。こんな記述をネットで見つけた。
The W88 warhead belongs to the newest missile warhead family,sharing a design similar to the W87.
It was designed for use on the Trident II (D5) SLBM. It combines a relatively high yield
with increased accuracy to make it an effective hard target kill weapon.
It is hardened against nuclear effects, and has enhanced safety features.