Lulzbot TAZ Upgrade 3D Printing Build Bed TAZ_4 TAZ_5 Leveling Tray for Taz 4/5 Replaceable Bed Upgrade (Note: This item is just one component of the upgrade.) The entire bed is clear of obstruction so the entire print surface can be used regardless of type of extruder or even a dual extruder. Nothing protrudes above the glass bed surface, anywhere. PEI can be omitted (with the use of enclosure) so no more hopelessly stuck parts. Use hairspray for trouble free adhesion. But any type of surface can easily be added to the glass.Multiple glass beds (perhaps with different surfaces) can be kept on hand and swapped in seconds. The only adjustment would be the Z knob. Actual level would never change with change of glass bed since the leveling portion never leaves the printer. The bed is held in place by powerful magnets pulling down creating friction with the silicon heater pad which is in direct contact with the glass. So, the bed won\\\\\\\\\\\\\\\’t move unless you want it to. Easy to remove glass beds can be lifted out immediately post print without tools for quick cooling and MUCH easier part removal, all without altering bed level in the printer. Leveling the bed is much easier than stock as well. It can be done in just a few minutes. The stock version took forever to level and required a hex drive to do it. And access to the screws was sometimes obscured making leveling often an excercise in frustration. But, with this upgrade, no tools are necessary, just adjust the two thumb nuts which are always easy to access, to quickly get your bed system ready to print on.