Siddharth k. 5 Reviewing this after a month after having it used every weekday.This is an amazingly comfortable chair. I spend 12 to 14 hours on it everyday with the laptop on my lap and work. I am never too tired and my back no longer hurts.The operations is manual and it has 3 positions. I have not used the 3rd position(flat) so not sure how comfortable it is to sleep on the chair.The lever is needed only to release from flat position. For moving from 1st to 2nd, 2nd to 3rd you just need to sit and push back till chair locks in. To get up from position 2 you will need to use arm rest and pull to apply pressure on footrest. this will be difficult at first but once you get used to it and chair is regularly used it becomes very easy. However I am 180cms tall so it may not be easy if you are very short(I am guessing). I have recommended this to my friends as well for use during this Corona time and would recommend others as well.There is one small point that I had read in a review about the chair leaving black mark on the floor due to the rubber padding under the legs. That happened for me as well but is cleaned easily.