Sealing Wand

The Sealing Wand, also simply called "the Staff", is a pink magical wand about a meter in length.

Its main speciality is to allow whoever wields it and provided they have magic the ability to summon Clow Cards at will.

The head of the staff is shaped like a bird's head with red gems for eyes and a beak and tiny wings on the back of the head. It allows people with magical abilities to Seal escaped cards and later on transform Clow Cards.

Although people without any magical experience require the Staff in order to manipulate the Clow Cards trained magicians may be able to activate cards either with objects similar to the wand (as demonstrated by Li Syaoran and his Sword on many occasions) or entirely by force of will alone (as demonstrated by Clow Reed with the Flower Card in episode 68).

Forms
During the course of the show the Staff is shown to be changed into multiple forms.

Dormant Form
When not in use the staff reverts to its dormant (or key) form. This form looks just like the active form except it is scaled down to a few centimeters in size (enough to fit in the palm of ones hand) with the main shaft being gold instead of pink. It also has two small prongs thrusting out perpendicular to the main shaft at the tail end so it looks like a key.

Whenever it's not being used, Sakura usually hangs it on a chain around her neck and keeps it with her at all times just in case there's trouble about.

When the Staff is in its dormant form it has the power to unlock any door that has been magically sealed by the Lock and is the only known way to draw out this card's true form.

Card Form
Sometimes certain cards naturally manifest when activated by the user by combining with the Staff. The only two cards known to do this are the Sword, which changes the staff into a rapier, and the Fly which increases the size of the staff's wings tenfold so that one can fly on it like witches do with broomsticks although when Sakura gained her Star Ward, the Staff couldn't handle using Sword and Fly at the same time so Fly instead manifested itself on Sakura's back.

This gives her the ability to fly while also being able to use the Staff for anything else.

Star form
When Sakura Kinomoto captured all the cards and passed the Final Judgment, the head of the Sealing Wand changed from a bird to a yellow five pointed star inside a circle with a small feathered wing either side due to the fact that Sakura's powers came from the stars.

This form retained all the powers of the old one but also gave Sakura the power to change the cards into Sakura Cards although in the beginning, it drained her of her energy, physically, emotionally and mentally, leaving her exhausted and prone to falling asleep.

However, she later grew stronger and was eventually successful in changing all the Clow Cards into Sakura Cards.

Guardian Form
When Yue & Kero possessed the Staff it changed. The wand's main shaft grew to around three meters in length and the circle around the star head disappeared. The wing also grew in size.

This form had all the abilities of the old star form but had much more magical power.