The crystalline polymorph Form I of -4-4-4-4–5-tetrahydro-5-furan-3-ylmethoxyphenyl-1-piperazinylphenyl-2,4-dihydro-2–1-ethyl-2-hydroxylpropyl-3H-1,2,4-triazol-3-one represented by the formula I . The level of distortion and amplification are determined by the position of the foot pedal with a low level of distortion and amplification when the foot pedal is in a released position and a high level of distortion and amplification when the foot pedal is depressed. A center beam may project upwardly beyond beams to either side of it to create a curved profile in which the wire mesh is curved along an axis of the support to slope downwardly on either side of the center beam. 04 or more in the element ratio.