Duskdeep is a unique Full Helm.
Its boost to all resistances is useful particularly early to mid game, but the reduction to Light Radius may make it better to equip on a hireling.
Stats[]

Duskdeep
Full Helm
Defense: 45-60 (varies)(Base defense: 23-26)
Durability: 30
Required Strength: 41
Required Level: 17
+8 to Maximum Damage
+30-50% Enhanced Defense
+10-20 Defense
All Resistances +15
Damage Reduced by 7
-2 to Light Radius
Normal Helms — Biggin's Bonnet (Cap) • Tarnhelm (Skull Cap) • Coif of Glory (Helm) • Duskdeep (Full Helm) • Howltusk (Great Helm) • The Face of Horror (Mask) • Undead Crown (Crown) • Wormskull (Bone Helm)
Exceptional Helms — Peasant Crown (War Hat) • Rockstopper (Sallet) • Stealskull (Casque) • Darksight Helm (Basinet) • Valkyrie Wing (Winged Helm) • Blackhorn's Face (Death Mask) • Crown of Thieves (Grand Crown) • Vampire Gaze (Grim Helm)
Elite Helms — Harlequin Crest (Shako) • Steel Shade (Armet) • Veil of Steel (Spired Helm) • Nightwing's Veil (Spired Helm) • Andariel's Visage (Demonhead) • Crown of Ages (Corona) • Giant Skull (Bone Visage)