Designed for environmental surface sampling this sponge works well for those hard-to-reach areas. The sponge adheres to a holder that is screwed onto a handle. Both the sponge andhandle are sterile. The polypropylene sponge and handle fit inside the 24-oz, write-on, Whirl-Pak bag. To use, add the buffer of your choice to the bag to hydrate the sponge. Once sampling is completed simply insert the sponge back into the bag and unscrew the handle and discard, drop the sponge into the bag, close and send into the lab for testing. 50/box.