DnD 5e DMG
Rod
Varies requires attunement by a warlock Requires Attunement
While holding this rod, you gain a +1 (uncommon), +2 (rare), or +3 (very rare) bonus to spell attack rolls and to the saving throw DCs of your warlock spells. In addition, you can regain one warlock spell slot as an action while holding the rod. You can't use this property again until you finish a long rest.