Instruction: Answer the given question by extracting information from the supporting document.

Input:
Question: I received the new headset but the SN is invalid on the Monstercable website. What's wrong with this pair?
Document: I had these for about a month when the plastic headpiece snapped when putting them on (normal use). I got onto Monster's website to make a warranty claim and was shocked to find that the serial number was invalid - it was a fake!Beware. The packaging and product looked (and sounded) legit, but it was not.
ATTENTION!!! I bought it from Amazon own store. The plastic headpiece snapped when I putting them on (normal use). And I got onto Monster's website to make a warranty claim and was shocked to find that the serial number was invalid. I cannot believe Amazon is selling fake product. Beware and Check the serial number before you decide to buy. But frankly, the sound of this is great.
Just received these from my wife. The sound is right on. I've tried Beats, and to me these are better. I'm not sure what more you can ask for as far as sound and quality. It would have been nice if they were foldable or came with a storage bag. I ordered a pair for my son for his upcoming birthday and I'm sure he's going to love them. And for the price, $59.99 ( they've went up since) you can't beat them.
It's totally worth it! I tried diamond and Solo, the sound quality are just similar (maybe it were just my ears that couldn't tell the difference). Given the price, I think N-tune is value for money. The only problem is with the SN which cannot be verified on the Monster's official website. The first one failed to pass the authentication and so did the second one Amazon replaced for me. I just hope my headphones will work for a long time without problems.
I buy this from amazon.com and i found in monstercable.com that they are fake that is so dissapoiiiitinggg im angry....thats why they are so cheap
Shape of cool a headset, the price is reasonable also, the bass is very good! The only drawback is not folded. I hope that manufacturers can improve this
I normally use the headset, but I do not know why it's recent first beam broken. I can not understand, just after the refund period.
NO BEWARE! I just discovered the one I bought was a knockoff. I went to Monster Inc website and did a serial number search only to find out it was a knockoff
it's fake,and you should not buy it.markings and stickers than original and legit Monster headphones.&#34; I checked the serial number on the Monstercable.com site
The latter two has more of a full sound with a punchy bass. You can not go wrong with either.
Answer: You may run into the same issue that I did which is - if the pair breaks, there is no warranty from Monster.