Protecto PF A10 and Protecto PF A20 are bitumen impregnated wool-felt boards. These materials have the effect of stabilising metals and plastics - giving rigidity and additional weight. The effects are combined to improve anti-boom results. Effective anti-boom measures aim at preventing the propagation of	body-borne sound waves. The transmission of sound is also prevented. This effectively and successfully prevents the propagation of air-borne sound. Protecto PF A30 offers the additional benefit of excellent adhesive strength and high flexibility even at low temperatures.