Convenient, easy to handle cartridges fit into the bottom section of standard glass or plastic desiccators. Cartridge consists of durable, longwearing polyester felt bag with a perforated Mylar® cover sealed in place. It is filled with Natrasorb® TI indicating silica gel beads which change color from blue when dry to pink when moist. Saturated gel can be regenerated in a 150° C (300° F) vented oven for 3 hours or more (depending on size), until blue color returns and may be regenerated repeatedly without degradation. Cartridges come individually sealed in a moisture-proof pouch ready for use.