This is a Grey Kinnarps Ergonomic Fully Adjustable Office Swivel Desk Chair Top Quality 1 Available 
Kinnarps are a great brand in commercial furniture
The Chair is really comfortable. with many functions. the Seat, Arms and Back are all Adjustable. The chair has a sest lock tilt.. It also has a seat depth adjustment. plus the arm pads can go forward and back as well as side to side
Very Good Chair. there is a couple of minir marks on seat. all quite minor, New this chair would be around the £800 Mark
approx seat max height is 55cms Seat width between arms is 46cms and seat depth to backrest is 43cms
Please look at my other commercial items