The new Ashtree twin lens mirror has a standard main lens and a wide angle lens below. Both lenses can be adjusted which allows the absolute best possible field of visibility to be obtained for the operator.
Tests on machinery have shown the outward field of visibility of the wide angle lens to extend to 5 metres from the side of the machine. A similar distance was achieved backwards where the mirror had been positioned to pick up on the area around the rear axle and then view back from there.
The main lens was positioned so that the standard rear visibility expected of such a mirror was achieved.