The front wheel of L10 tractor is in front of the torch for leading.It can guide along the groove of work and make inside girth or longitudinal welding without guid rails.
L12 tractor is a three-wheeled welding tractor that can work with or without guide rails.
When using standard guid rails, L12 is suitable for straight flat and flat fillet welding.
When using without guide rails, the front wheel can be steered to make flat welding on a curved surface. Or the angle of front wheel can be set to make flat welding of circular welds.