Instruction: Output yes if the supporting document can answer the given question. Otherwise, output no.

Input:
Question: hey will this mag fit a M4 viper by black op?
Document: This is a great flashmag. I bought this magazine to go with my newly purchased KWA SR10 M4 (2013 model) however it has a VERY tight fit. It basically gets stuck in the gun whenever I put it in. This is not the magazine's fault.
I bought this for my first airsoft M4. It's a little bit of a snug fit on my lancer tactical m4 S system yet it works great. Three pulls of the string and I can shoot non stop. Feeds well.The only small problem with it is that it's a scratched when I was loading it into the gun because of the tight fit even though I don't mind it. It looks like it's been more used that way.
If I were to say anything about the Commando M4 Flash Mag, I would say it's average. I bought two of these earlier this year, and while one works like a charm, the other experienced malfunctions after about 10 days of use and is now slightly inadequate. It is solidly built and the ripcord feels good, but heed my warning: do not pull the cord more than 5 times! The cord gets difficulty retracting and the whole magazine can experience problems.
With just a few pulls on the rip cord and I can run the whole mag, definitely worth the money.
Hey guys, I am not associated with Vida at all. In fact the only reason why I bought from these guys was because It is from Illinois Instead of California (I live on the East coast). This way it would get here faster. Anyways Vida said it would get here within five days, but the package arrives in two, and the package is marked Expedited 2 day shipping! Which means they payed for my convenience!
First day out with mags (I ordered 3) 2 were fine and worked great, the third one broke on first pull of string. Maybe I just got a bad mag, I will know more after I can use them a bit more.
I thought from the reviews etc. that this Hi-Cap mag would work on my King Arms M4A1. No such luck.I did not return because I waited too long. That is my fault and not the seller's.It should have worked on my AEG though.Better if you buy local on some items.
I had this mag for 3 weeks and it eventually broke on me, partially my fault. With flash mags, it is like a regular hi cap, but instead of the wheel at the bottom, there is a cover in the bottom in which you take off, then there is a little piece of plastic with a string in which you pull, and it winds it. After you don't have to wind for about half the mag.
I took the clip on a pen cap and glued it onto the back side of my mag. Took a knife and cut it so it was just a little bit thicker, causing the mag to constantly stay forward and it feeds fine now.I would reccomend this to someone who like high caps more than mid caps
I've just received this magazine and it's my favorite high cap mag. It fits my JG G36 1608-6 AEG better than the two high cap m4 style mags that came with it. Best of all, no more annoying winding in the middle of a fire fight. 3-4 pulls of the steal cable and she's good to go.
Answer: yes