Unit is designed for free dome blowing of heated thermoplastic sheet (cast acrylic recommended) using air pressure supplied by vacuum forming machines or from an independent source. The 6, 9 & 12" clamping rings (dome diameters) mold a 0.375" max. material thickness. Features integral pneumatic valve for blowing process control, durable rubber seal plate with air diffuser and fully adjustable toggle clamps. 110 VAC. Requires heated thermoplastic sheets. Shown with fan-circulated oven (see below).