AWMS-3-137S4 is a triple mount with medium post, usually for using 3 x 24" or 27" displays. The sliders on outer arms allow greater flexibility in monitor size and cockpit creation. AWM-P40G-W: Atdec 400mm Medium Post With Guide Marks White AWM-A13T-W: Atdec AWM-A13T 130mm Short Swing Monitor Arm, Adjustable Tilt and Pan, White AWM-A71T-W: Atdec AWM-A71T 710mm Long Swing Monitor Arm, Adjustable Tilt and Pan, White AWM-S-S: Atdec AWM-S Monitor Slider Accessory Silver AWM-FH-S: Atdec Heavy Duty F-Clamp Desk Fixing Silver