Abstract: An adjustable slot coater die (500) for use in a rotary coater device is provided, comprising a die manifold (502) into which hot melt material may be introduced and having a plurality of distribution channels; and an adapter (506) reversibly attachable to the die manifold, the adapter including at least one die opening (552) through which hot melt material may exit the die. The die opening (552) is formed by a notched shim plate (552) disposed between the adapter and a mouthpiece (508) attached thereto. Selected manifold distribution channels (530) of the plurality may be sealed to prevent hot melt material from exiting the manifold through the sealed distribution channels. The manifold also includes (i) a filter for filtering the flow of hot melt material flowing therethrough, and (ii) a plurality of heater cartridges installed at locations (536) therein.