First appearance: Episode 106 (Uranus and Neptune); Episode 111 (Pluto)
The Lip Rods were transformation items that belong to the Outer Senshi. Haruka Tenoh, Michiru Kaioh, and Setsuna Meioh used them to transform into Sailor Uranus, Sailor Neptune, and Sailor Pluto. To undergo this transformation, they would shout the phrase "Uranus/Neptune/Pluto Planet Power, Make Up!" (respectively).
The Lip Rods were exclusive to the anime, as during the third arc, the Senshi (aside from Sailor Moon and Sailor Chibi Moon) didn't require magical items to transform. Unlike all of the Inner Senshi's wands, which were all identical save for the color and planetary symbols, the Lip Rods were very distinctive in appearance; only the handles were identical. This could represent how, unlike the Inner Senshi, the Outers were rather independent and not as unified.
The origin of the Lip Rods is unknown; the Inner Senshi received all of their items from Luna and Artemis (or Pegasus), but the Outers are not shown to have any such benefactors. When Haruka first encountered a Daimon, her Lip Rod appeared from thin air right in front of her; the same probably happened to Michiru and Setsuna (after she was sent to the 20th Century, that is).
The name "Lip Rod" comes from the toys released by Bandai.
As you can see on the boxes, the toys of the Lip Rods doubled as lipstick. This is why the Outer Senshi finish off their transformations with lipgloss; it's actually a very subtle advertising technique.
The Lip Rods are the rarest, most expensive, and most highly sought-after Sailor Moon toys, only challenged by the Orgel. In particular, Pluto's Rod is the rarest toy of all.
Sailor Saturn was never shown using a Lip Rod (as she never got her own full-fledged transformation sequence). However, in the fandom, her theoretical Lip Rod is universally represented as a sphere encompassed by a ring, representing the planet Saturn (the picture of her Rod is from a fanmade transformation video).
The Outer Senshi were never seen transforming during the Stars season. Therefore, it's unknown if they continued to use the Lip Rods to transform into their Super forms or if they used something else.
The Lip Rods are the only wands ever used by the Outer Senshi; in the manga, they didn't need any items to transform before their Super transformations. From their Super forms on, they used their Sailor Crystals to transform.