Christy’s Ultra Seal™ is an all-purpose thread sealing compound, containing Teflon® for easier assembly/disassembly. Ultra Seal™ is a white, brushable, grit-free, smooth paste. Ultra Seal™ provides a leak-free seal on most types of metal and plastic threaded applications. It’s non-toxic, non-seizing, and non-hardening. Ultra Seal™ does not transfer..