SIIG (CE-MT1P11-S1) Easy-Access Full Motion Monitor Desk Mount - 13" to 27" PREMIUM QUALITY - durable gas spring assisted full-motion desktop mount provides smooth, precise and effortless viewing height adjustment STURDY & STABLE - Supports flat-panel monitors from 13" to 27 and up to 19.8 lbs. (9 Kgs); Heavy-duty "C"-clamp is compatible with desk surfaces from 0.4" to 3.3" in thickness and grommet mount fits through surface hole from 3/8" to 2.25" wide and up to 3" thick ADJUSTABLE GAS SPRING TENSION - Adjust tension of Gas Shock using included 6mm Allen Key. Turn clockwise to reduce tension for lighter monitors and counter-clockwise to increase tension for heavier monitors ERGONOMIC COMFORT - arm mounting height range up to 3.8", supports tilt angles of +/- 90, pan angles of 180(left/right) and 360 arm swivel for best ergonomic viewing position; 360 rotatable VESA plate supports portrait or landscape monitor orientations and arm extends up to 20"; ELIMINATE CABLE CLUTTERS - Cable management clips included to keep cables neat and organized