Four-channel analog inputs module is a data acquisition module that provides direct connection to four analog signals of the same input type and range to any host with an RS232 or RS485 port. This module provides direct connection to a wide variety of sensors and performs all signal conditioning, scaling, linearization and conversion to engineering units.

Four-channel gas monitor is a system used for continuously monitoring combustible gas concentrations in four locations. It consists of four remote catalytic sensing assemblies and a solid-state controller. The controller features four independent channels, each having its own circuitry. It features a digital display of gas concentrations in % LEL for each channel.

Four-Directional Lift Trucks includes control means for placing the truck in a carousel mode. It allows to create narrower aisles, denser storage and retrieving long loads faster and more easily. Its mechanism provides the smooth and easy. It performs several functions simultaneously by place, pick, and move big loads delicately and smoothly. It can reduce storage space and handle long, bulky loads with less damage.  Lumber, drywall, fiberboard, furniture, pipe, and other big loads are used to move more easily. It is ideal for long loads. It comprises with two front wheels and one rear wheel, each wheel being directionally adjustable by rotation. It allows narrower aisles, denser storage and retrieves long loads, faster and more easily.