The UJK Technology MultiFunction workbench top is 18mm thick Valchromat. Valchromat is not MDF it is a type HDF. Valchromat has greater internal cohesion, higher mechanical strength and is more moisture resistant than MDF. The UJK workbench top has a grid of 20mm plain dog holes: 11 holes by 7 holes. These holes are CNC machined to guarantee accuracy, aligned lengthways and widthways with the rows perfectly square to each other. These dog holes allow you to use Parf dogs and many other accessory clamps, guide rails and stops to hold, saw, rout and machine your work with spot-on accuracy. The top size is 1,102mm x 718mm and is a snug drop-in fit in the UJK Technology MultiFunction workbench frame and the Festool MFT base making it a suitable replacement for the standard Festool top.