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

Input:
Question: How does this slider install onto a tripod, Is it by a fixed quick release plate on the bottom of the slider or does it attach by 3/4" screw?
Document: when i mount my gopro tripod attachment, it doesnt sit straight, its off to a 45 degree angle, (not sure if this is intentional)  but i have to either slide it loose, or mess with the attachment to preset it at a 45 degree angle before i screw it on. i havent tested this with a normal camera, so im not sure if its just my mount, but it does that to 2 of the mounts i own.
The head of the nylon Brake screw twisted off the first time I used it. I was also hoping the trolly would be a little tighter, but that may be expecting too much. Overall though it is solidly built piece that will not deflect under even a heavy camera if mounted on a single tripod. The more I practice, the better my results.
When I first received the product I was very pleased. The construction looks great it's packaged well. it's pretty much as advertised. I couldn't wait to start using it. That's when I noticed a problem. There is a clicking that happens every 1/2&#34; to 3/4&#34; of travel. The click isn't just annoying. you can hear it in the recording plus you can see a jitter everytime it happens.
good low budget slider. fairly well built. had a bit of trouble sorting out how to get this on my manfrotto tripod, but finally sorted it out (no instructions).
A Canon 5D markii and a Canon T3i. It handles the weight of both just fine with room to spare. The friction screw works awesome as well. You can tighten it just enough at a near vertical slant to allow the slider to move as it would sitting on a level plain.It's very robust as well. Very tough and rugged without being to heavy.Anyway, I have to go now. My wife is literally going into labor..... Seriously.. Right now....
Bottom line, get this item, it will not dissapoint.
I bought this at the last minute to fly tow FL for a set of interviews. I was trying to avoid excess baggage charges and my Dan Dolly would have broken the bank in that regard. For the $, it works great! You have to let out the set screw all the way for it to really work smooth, but once you do that, it was great.
This thing seems to be very wall built, and is pretty heavy. You can use it with a tripod, or you can use the legs that comes with it,  But again it is heavy and the cheap tripod I have will not hold it steady.You can also mount it vertical for up and down shots. Overall it is a great buy and I would recommend this product.
I've tried twice now to contact the seller via their website and they have not even responded.I'm sure I got a dud because everything else about the unit is high quality. Unfortunately I can't use it and the reseller doesn't seem to care.This kind of customer service is not acceptable. It's unfortunate because I was planning on purchasing a tripod from them but won't now.
I like this, i'm sure the $800 models are worth their weight, but on a budget, this has proven to be simply awesome. It is solid, well made, does the job (use an elastic band to pull), and is reasonably long.I would highly recommend, 4 instead of 5 stars because its not perfect, and i suppose in many cases that is why you'd pay $800 for one. but, it works and works well.POLO
Answer: I attach my arca plate at the bottom, you can position it center, left or right...