Instruction: Given a question and the related document, and generate the answer to the question based on the information provided in the document.

Input:
Question: tell me the size
Document: I haven't had them long enough to rate the durability, but they appear to be well made. Time will tell if they do the job I expect them to do.
This pillow encasing was easy to put over my queen pillow and didn't affect the comfort of my pillow like other models have in the past. Also easy care and I can tell the difference in how I feel after a night's sleep.
This is my second Luna pillowcase purchase for another pillow in the house. Ever since purchasing these pillowcases I have stopped sneezing when laying in bed. You can't even tell its on there either! Thank you Luna!
To my experience this product is not down pillow friendly. This pillow protector does not allow air to flow through the protector which is one of the main things a down pillow needs. When my pillow is in this product, it feels like a hard rock when your supposed to sink in, you can definitely tell the air does not flow through this sufficiently.Also the terry part of the outside of this is very strong and able to be felt too much.
With the size of my adjustable bed this cover fits fine and doesn't come loose on the corners like sheets do. This helps the sheets stay in place
Needed a new cover for my ridiculously expensive new pillow. The queen size cover was a perfect fit. It washed beautifully as well.
The Luna zippered pillow cover is exactly what I wanted, and at a good price. The Queen size fits a thick standard-size pillow very well.
Nobody else had confirmed this, so felt the need to post. This fit my medium height, queen size, Tempurpedic pillow. The fabric has a great, terry cloth-like feel also.
True to it's size. Great quality for the protectors, great customer service and care. I ordered from 2 different  popular companies for the pillow protectors; After overall comparisons, I'll definitely come back here for my next order.
I have a pillows one calls an investment of sorts since it was much more expensive than what I normally buy. It is Queen size, so I was trying to find that size after the zipper split on a cheaper King size cover I was using. This fits perfectly. Of course, it is also a bonus that it is Made in the USA.
Answer: The standard  size cover is 18 inches by 25 inches.  It fits standard size pillows perfectly.  If you have a queen size pillow, you should order the queen size cover.