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: How does the mount handle teardrop shaped seat post?  Does the trailing pointy edge cause the light to shift to the side after a few bumps?
Document: This is one bright light. It came with brackets for seat post, handlebar, and also for a rear rack which is where I wanted to mount it. It clips in the brackets pretty tight, but can be easily removed. It has not budged in spite of going over some serious bumps.
Beside the lack of rear angle projection, the light dimension is a tad thick. If you just want to mount it onto the seat post, or the saddle bag rack, it won't be a problem. For me, I like to mount it behind my and my family members' helmet. The higher the light sits, the greater the distant the light can notify our presents.
Build quality appears good, and the mount bracket options allow flexibility in mounting between seat post, seat stays or rear rack if you have one. Light locks into the bracket and is easy to click in and out when leaving the bike parked.Best value high-power tail light I've been able to find to date.
Pros are;1 - well built (but heavy if you obsess about such things).2 - comes with a mounting bracket and screws for rear rack, seat post and seat tube. Very few lights come with brackets for a rear rack, so a big plus for me to mount on my tourer.3 - bright and with a good flash pattern. The flash pattern is unique in my experience.4 - single button for on/off and flash pattern change.
It comes with 3 different mounts. The bracket mount worked great with my rear rack and has the same spacing as a standard rear reflector, plus a wider, horizontal mounting option, too. The other two mounts are for the seat post and for the seat stays (the part of the bike frame that goes from the top tube to the rear axle).I commute daily 11 miles roundtrip by bicycle on urban streets and I love this taillight/reflector. It is perfect.
This tail light is bright and it is definitely visible from behind. I do notice that most drivers will pull further to the left when passing. Directions suggest two locations for placement, one is the seat stay and the other is the seat post. I tried both and I got much better visibility on the seat post - as high as possible and centered on the bike.
This light is so bright it will hurt your eyes at night or in the day time. At night I will look behind me and the whole neighborhood is flashing red as though a police car pulled into someone's driveway. Drivers would have to be blind to not see you. The mounting options are very useful for a rack or seat post. Great job Portland Design.
I do not know the lumens of this tail light. But when I attach it to my seat bag and turn it on  the light can be sen a block away a night. It is not as visible during the daytime. I like that it comes with several different ways to attach it you bike. You can clip it on your seat post, attach it to your seat bag or  panniers, or rear bike rack.
There are many different lights out there.. this was bright (red light even though it looks as though it would be white here) and controls were easy enough. This attached ok to bike seat post. But it is too big to put on the bag of bike bag if that is where you want to place it. It is better than what I have on my bike bag now for brightness, but I went with the other brand as it is very small.
The light is as bright as you are going to get in a non rechargeable light. My first ride I had another commuter come up and comment on the flashing pattern (zzzPOP). He was following me and thought it was a good mix of steady (so cars can gauge distance) and flashing (grab their attention). My only issue is that the seat stay mounts are round so it would only fit on my seat post (many carbon stays are not round).
Answer: no