<p>The present invention provides an adjustable venturi device designed for efficient use with blowers of various different capacities. The venturi device of the present invention includes a blower feedable positive air passage and a negative pressure air inlet exposed to and operated by air draw from the positive air passage. The venturi device is adjustable for varying exposure of the air inlet to the positive air passage with resultant varying of the air draw according to capacity of the particular blower used with the venturi device.</p>
