Delicol Office Household Swivel Chair Mount Aluminum Adjustable Ergonomic Keyboard Laptop System+chair Mount Mouse Try(walnut) Got a neck or back pain when you leave chair's back rest for long time?Don't feel comfortable when you playing a PC or TV game?Then you should need this one-Delicol Ergonomic keyboard Laptop tray system. Frame is Made of stainless steel and aluminum alloy,Tray is made of HDF,mouse tray is made of ABS plastic. Ergonomic design,the panel can be rotated 360 degree,people can leave chair easily.Panel measurement:17.8"*9.85" Package includes:1pcs keyboard tray and 1pcs mouse tray Note:The chair cylinder bar's diameter must be 28mm(perimeter is 88mm),plz make sure to measure your chair's size before ordering.