The Standard 200 Series:
Kimberly-Clark developed Block-It 200 Series fabric to be a mid-price leader in quality and performance. It uses 3-layer polypropylene construction for moisture and dust resistance, and the fibers are treated for extra UV resistance. This U.S. made fabric offers good, basic protection and is an excellent value.

The Deluxe 300 Series:
Providing a protection level between the 200 and 400 series fabrics, Block-It 300 Series uses a 3-layer construction process, with an inner layer of polypropylene melt-blown sandwiched by an inner and outer layer of spunbond. The fabric shares the features noted on the Technalon cover below, just at a reduced performance level and reduced cost.

The Technalon 400 Series:
Block-It 400 Series, (formerly known as Evolution 4) uses 4-layer polypropylene construction for maximum protection in all weather condidtions. Often imitated but never equaled, this U.S. made fabric is used by millions of satisfied car enthusiasts around the world.