Is this one mask or a tub of multiple masks?

It is a tub containing 30 sheet masks, with 320 g of total contents.

How long should I leave each mask on, and what do I do afterward?

Leave it on for 10–20 minutes, remove the sheet, then gently pat the remaining essence into your skin until absorbed.

How do I remove and apply a sheet from the container?

After cleansing and toner, use the included tweezers to lift one sheet. Apply it evenly so it adheres closely to your face, then close the lid tightly after use.

Does the essence leave a sticky finish?

It is described as lightweight and hydrating, with comfortable absorption and no sticky after-feel.

What skin concerns is this mask designed for?

It is designed for dry, dull-looking skin and concerns about visible dullness or uneven-looking tone.

Is this intended for daily use?

Yes. It is designed as comfortable, gentle daily sheet-mask care.

Does the 99% claim mean that the finished mask is 99% vitamin C?

No. The wording refers to the purity of the vitamin C material, not the percentage of the finished mask. The formula separately lists its vitamin C forms in ppm and ppb.