Instruction: Given a question and the related document, predict if the question is answerable based on the information provided in the document. Output only yes or no.

Input:
Question: Does LaserMax make a guide rod with a green laser for a Glock 21 sf Gen 3 ?
Document: I have used the red lasers for a number of years, as I have been around weapons for some time. I was in the US Army for 21 years. Somebody told me of the green lasers. I searched and found this one that mounts the same place as the operating rod on my pistol. It is very easy to install, if you can field strip your pistol then you should have no troubles installing this kit. Hardest part is switching the slide lock and slide lock spring out.
Change the slide lock spring and then using the tool depress the spring and slide the new, provided, slide lock in place. The laser itself simply replaces the factory operating rod and spring. Once installed the green laser is very visible and this one pulses quickly. I have not taken it to the range yet to check for accuracy, but it lines up with the barrel, so I am willing to bet it is very accurate. The company that makes these is in Rochester N.Y.
This product is exactly as described and what you're expecting.The green laser is extremely bright and incredibly easy to find. You really can't miss it! The pulsating dot is unmistakable and the clarity at great distances is amazing. I have not measured just how far I can still see it, but it has covered a much greater distance than I can shoot a large caliber pistol accurately anyway.The on off switch is great. While it moves easily enough when you mean it to, I have never accidentally activated it.
I sent it back. Only worked Periodically. I should have not bought a used one. Now I have a new one that works with a five year guarantee and a $90 dollar rebate from Lasermax.
You must use the replacement spring for under the take down tool. It is much tighter than stock so it holds the switch up to maintain good contract and slight raised bumps for lack of a better word hold the switch in it's on and off positions firmly. You will notice that difference when field stripping the gun.Anyone who owns a Glock, or other model of pistol that this sight is made for, should already be more than familiar with installation. Sighting is dead on.
I followed a YouTube video & installed in a few mins. Registered & have a 5-yr warranty. Bright laser & works very well. I prefer the internal laser as it's always aligned & can use my existing holster.
It's incredibly flawless in design, and the recoil spring so far seems indiscernible from the stock spring.For anyone who is considering a laser sight of any kind, I cannot find any reason to get anything other than this save maybe that it is expensive, but how much is your accurate protection worth?Edit 5-30-14:Don't purchase. Laser simply stops working. If it hadn't cost nearly $400 I would have expected that. Complete fail.
The only thing is it makes the gym shoot alittle hard but other than that I like it thinking about buying another
I bought this and sent it back after reading all the reviews of how bright it is. It is NOT! cant see the dot outside if the target is on the bright california sun over 15 feet away. Forget it. great design, good for in the dark, but dont use it in the daytime. Btw its not just this copy, the other two i ordered were the same.
Answer: yes