Instruction: Answer the given question using the supporting document.

Input:
Question: What is the straw made of? (plastic or stainless steel?)
Document: Very nice, good looking as well.Just knowing its stainless steel makes me feel better about how clean I can keep it.My plastic cup got to the point I could not get the bad taste out even using bleach.I have not had it very long yet, but I am sure I will have no complaints.
Nice, insulated cold drink cup. Nice and big. I haven't used it for Hot, and probably wouldn't, because of the plastic straw and plastic lining on the lid. I don't like plastic, but for a cold drink, the little plastic in the lid makes minimal, if any contact with your drink. We will probably get some stainless straws, as well!The cups are nice looking, and we were thinking of getting a car decal or something to put on them so we can tell them apart and to decorate them...
I replaced the plastic straw with a stainless one from another Amazon Seller. I use this every day, all day for nearly 6 weeks and I've had SO SO SO SO many compliments on this! It's a great size, insulates well, stands up to hot, cold, acidic lemon, smoothies-whatever and fits well in my cup holder in my car (the small one and the big one). I've added stuff like Mio water enhancer and was concerned that it may stain and it's been perfect. I've been careful not to submerge it into water (per enclosed instructions-neither the cup not the lid)My only two unsavoury feelings are these: The inner part of the lid is plastic-though it's quite sturdy, and I've had no cause for concern, I'm hesitant as plastic things break eventually.
This is the best stainless steel tumbler I've ever had. If i put ice in it in the morning, it's still ice when I go to bed! It's incredible!
Love the cup! Has a very sleek and great look to it! I like the straw that comes with it, however I'm buying separate stainless straws. If you are planning to use the straw that comes with it, make sure you get a brush to clean it. Please note that although it says its 18 oz, it really only holds 16 oz because of the insulated lining. Will update if anything goes wrong..but hopefully I won't have to. :)
I'm scared it might break one day and I won't have a replacement-but like I said, I worry about everything all the time, so if you're normal, you'll be fine with it and won't give it another thought. The second unsavoury feeling is that when you screw the lid on all the way, there's a bit of wiggle room, like the lid wiggles back and forth just a little bit. It's not a big deal, like no leaks or anything (well except the straw hole) but when it wiggles, I worry the plastic will break, so I'm careful when I screw the lid on-don't reef on it to close it, take care of it...Other point to mention is the inside of the cup is matt, not glossy.
There's nothing wrong with that, just worth a mention. My added stainless straw has mildly scratched the inside bottom of the cup, like maybe two or three lines, not a big deal. considering how much I've used it and abused it, it's standing up remarkably well. I'm almost considering buying another-JUST IN CASE something happens. Like I said, I've had so many compliments and so many people want this now, I should buy them as gifts for Christmas!
This is the best cup on the market! It keeps my ice water cold for hours even in the hot car! It is very well made...I can't wait to more!
These cups are just awesome. I use one for work and one for home. I put Ice in it at the start of my work day to keep my drink cold and by the end of my work day there is ice still in there. The thermal insulation is that good. Also great for keeping my drinks hot - but a little difficult drinking hot drinks through the straw.
This cup is far better than the plastic ones. Drinks stay colder because the ice doesn't melt near as fast. I love it.
Answer: It's plastic. A lot of people buy the stainless steel straws separately (as did I) but I think the original straw is just fine.