The Ultra Powrpak series for portable restrooms and holding tanks from CPACEX is formulated with a fragrance and dye to offer continuous odor control and fragrance for up to seven days in extreme temperatures and conditions, or for special events where overuse may occur. Effervescence ensures the packets dissolve quickly and disperse evenly throughout the holding tank. They are available in five sizes to fit specific applications and climates. The packs are biodegradable and contain nonstaining blue dye. 800/974-7383; www.cpacex.com.