The Solid Valve Liquid Pads for Storz & Bickel Volcano allow the device to vaporize oils and other liquids. The pads are durable. Made of compressed strands of stainless steel, the pads work great for vaporizing liquids because the individual strands ensure the liquid is distributed over a wide surface area. The solid valve liquid pads are best used for liquids; however, you can also use them for herbs. Before purchasing this product, ensure your vaporizer has the Solid Valve system. These pads won’t work with the Easy Valve system.