The Style 3423 monitor comes with the lift-off assembly shown on the left (click any picture for a hi-res version) a portable base with two 2-1/2" inlets and a direct mount adapter with 3" female NPT threads that can be permanently plumbed to your pump.  It is rated for flows up to 800 GPM on the ground base and 1250 GPM from the deck base.

The upper portion of this monitor lifts off and can be connected to the deck gun adapter (Style 190) which is sold separately.  The 3" waterway with cast-in vane is rated to flow 800 GPM as depicted and 1250 GPM when truck mounted. (Click on picture for a larger view.)

This combination monitor can be supplied with a deck mount as shown (click picture for larger version) or with a portable base with two 2-1/2" inlets.  When deck (truck) mounted it can be kept in the lowered position for clearance but raised above obstructions for use.  In the portable configuration the monitor may not be used in the elevated mode.