Wally Plug with O-Rings FatSac Replacement Ballast Bag Plug is used to plug unused holes on FatSac ballast bags. Fits the proprietary thread pattern used on FatSac bags making a perfect water-tight seal that won't leak or back out over time. Off-the-shelf FatSac ballast bags include the required number of bag plug fittings, but if you're misplaced one or want to have extras, this is the fitting you need to close any unused holes on the bag. FatSac ballast fittings have been designed with you in mind.  All of the fittings make connecting pumps and hoses to your FatSac a quick and simple task.  Features: * Wally plug * O-ring *Sold as an Individual Warning [https://productimageserver.com/prop65/6pt.png]WARNING: This product can expose you to chemicals including Diisononyl Phthalate (DINP) which is known to the State of California to cause cancer. For more information go to P65Warnings.ca.gov [http://P65Warnings.ca.gov].