Not sure of the fps of that one specifically, but as long as its less than 1 Joules (about 300fps) and smooth bore it is considered a toy. In that instance all the other questions – length, rate of fire etc do not matter, as it is classified as a toy. Provided its UK purchased it would fit into that classification unless extensively modified, which if it went over those fps figures would be VERY illegal. If it is already owned there are no issues with regards to possession. If you were attempting to purchase etc you would need to be a member of an airsoft skirmish centre etc as per the requirements of the Violent Crime Bill. Obvious common sense of treating it as if it is a firearm would apply e.g cased in public areas etc.