CPI's Weigh Better™ Pre-Weighed TSS Disks are pre-washed, pre-dried, pre-desiccated, and pre-weighed in accordance with Standard Methods 2540 D and are ready to use out of the box. To significantly speed up TSS analysis, simply filter your sample, dry the filter, and record its final weight. CPI Pre-Weighed Filters come affixed with a heat resistant bar code label pre-printed with filter ID number and the filter weight, they are fully compatible with popular automated TSS software and really are easy to use and can save you time and money when it comes to TSS analysis. 100/pk