Both the 1/16 inch and 1/8 inch polyethylene frits are a porous material designed to retain the synthesis support within the column. They should be used with our standard luer-fitting synthesis columns (CL-1501, CL-1502 or CL-1505) to make your own specialty columns. The frit pore size is 15 - 45 µm. They are compatible with all oligo synthesis reagents. The 1/6 inch thinner frit is more suitable when there is a requirement to have more CPG in the column, for example if it is a low-loading support or for larger synthesis scales. The coarse porosity frits can be helpful for more viscous solutions, however the normal porosity is fine for most applications.