This physics Air Table is perfect for near frictionless two dimensional motion to study position velocity acceleration conservation of energy and collisions. Kit contains:1 x Air table2 x Levelling Feet4 x Installed Table Bumpers8 x Air Pucks8 x Velcro Bumpers8 x Rail Pins8 x 0.245 OZ Donut Masses The air table is constructed of heavy gauge anodised steel. The workable surface is 65cm by 45cm with major graduation of 5 cm and minor graduations of 1 cm. It also has pre-installed flexible cable bumpers for doing movement launches collisions and a variety of other physics experiments. The rails above bumpers except rail pins for designing custom experimentsThe air pucks are made of durable plastic and masses can be added as well as Velcro bumpers for elastic of inelastic collisionsThis air table requires a blower (not included) most air track blowers will work. The outer diameter of the air input is 3cm.