Abstract: A vehicle to be moved in either of two mutually perpendicular directions, and including a first plurality of caster wheels, a second plurality of wheels rotatable on parallel axes to follow a common track aligned with one of the directions, apparatus for moving said second plurality of wheels into and out of contact with the ground, and coupling members for applying tractive force to the vehicle in either of said directions.

Abstract: An outlet fitting construction for thin-walled, flexible plastic tubing for fluid distribution systems. The outlet fitting includes first and second outlet members that in the preferred embodiment are threadedly engaged and have aligned axial passageways. One outlet member is provided with an annular rim with a riding surface that facilitates insertion of the outlet fitting into an aperture in the flexible surface irrigation tubing. In an alternative embodiment a tube piercing member is provided that is engaged with the outlet members so that the outlet fitting may be inserted into a tube which does not have pre-existing apertures.