These are not shields or guards. They have no waterproof backing and are not intended for standalone use. As designed, they absorb some urine while allowing the excess to pass through and into the main diaper/pullup thus increasing the absorptive capacity of the combo. Paired with the LivDry Ultimate pullup, they offer the fluid capacity of much bigger and bulkier tab style diapers without the bulk. Buy the length that is appropriate for your use. I use the 14" and position them so the top of the booster is about an inch above the top of the absorptive pad at the front of the pullup. This positions the booster for maximum coverage and fluid absorption while still assuring that they do not interfere with the rear "pouch" in containing fecal matter.