The MAVIC 845 was the long pulley cage derailleur in the MAVIC 840 series. It shared with its brothers the beautiful build quality, needle bearing pulley wheels, stainless steel pivots and fittings, Dura-Ace 7400 geometry and the ability to be completely disassembled (if you like circlips). It also shared the lack of Mavic’s signature eccentricity (whisper it quietly in the presence of Mavic aficionados - but I think Simplex may have played some part in its manufacture). This long cage version was particularly dull because it has very conventional looking steel pulley cage plates and weighs a ton.
This example is a later model, jazzed up for those zany, hedonistic, bad-ass, mountain bike boys with a colourful sticker. Groovy.