CRL EPDM Rubber Setting Blocks are more durable than Silicone Rubber Setting Blocks and have better resistance to the effects of weather and ultraviolet rays. They have been used successfully in past glazing applications in conjunction with Safely? (PVB) interlayer laminated glass. The composition of the blocks makes them resilient so that the glass cushioned by them can withstand vibration, shock, high and low temperatures, and heavy wind loads. A variety of sizes are available from stock. Product Warning: Do not use them with silicone sealants, as there is a potential for bleed-through of color.