Instruction: Evaluate the answerability of a question by analyzing the related document, outputting yes if the document contains information addressing the question, and no otherwise.

Input:
Question: The directions on this filter mention an "optional giardia filter"...are these included in the original filter or must they be ordered separately..??
Document: I became aware of this product four years ago and received one for myself. I am simply amazed by this technology which was developed for and sold to the military in the 1980s. While Americans do take many things for granted, it is clear that this product would be a &#34;life saver&#34; for many in our world. And even here... if you are an avid hiker or outdoorsman this product is a must for your vital supplies.
I traveled a lot and sometimes I am afraid of drinking the water in restaurants. This filter is so handy to have and i would strongly recommend every fast traveler to have one.
After researching the different filter straws I found that Pure Sip is used by the military because it removes everything including radioactive particles according to published test results.
My rating is for the size and design since I havn't tried the filter yet.If this filter is good enough for our Military its good enough for me.I would probably boil first unless I absolutely couldn't.
The funny thing about emergency preparedness is people forget how much water you need each day.After researching most of the options in the market, it was great to find this one was available for $19.99! The most important thing about filtering out dirty water is the product actually filters out the bad things. Many of these are visual like color or particles but the dangerous things are invisible like viruses. This device will kill all of the bacteria all of the viruses and quit working when it is done.
All based on the technology of this seemingly simply straw. I highly recommend and endorse this product.
Answer: no