Device for dispensing volatile substances with variable mat structures

1. A portable area insect repellent device having a housing for variable thickness mats, said insect repellent device comprising:

a source of heat and a heating plate, a mat located above said heating plate

and a grill located above said mat,

said mat carrying volatilizable material to be heated and dispensed to create an insect repellent area,

said housing comprising a floor and a heat box having an underside:

an adjustable compartment comprising said heating plate

and said grill comprising the top of said adjustable compartment; and

the underside of said heat box being vertically adjustable to adjust the size of said adjustable compartment, said adjustable compartment accommodating mats of different sizes, the size of said adjustable compartment being manually controlled by a user,

springs connected between said underside of said heat box and the floor of said housing of said device,

said springs vertically adjusting the space in said adjustable compartment,

said springs being biased pushing upwardly on said heat box.

2. The portable area insect repellent device as set forth in claim 1 , wherein said mat comprises at least two layers with each layer of said mat comprising a volatilizable material, said volatilizable material in each layer of said at least two layers being volatilized at different run times.

3. The portable area insect repellent device as set forth in claim 1 , wherein said mat comprises at least two layers, with at least one of said at least two layers containing a material that acts synergistically with the material in the other of said at least two layers.

4. The portable area insect repellent device as set forth in claim 1 , further comprising a locking mechanism to vertically lock the location of said heating plate.