PetSafe Pawz Away Extra Mini Pet Barrier Transmitter, PWF00-14040 (Pack of 2) Pack of 2 Mini Add-A-Barrier PWF00-14040. Can be used for pets 5 lbs and over. Waterproof and may be used indoors and outdoors. Compatible with: ZND-1200, PWF00-11923, PWF00-13664,PWF00-13665, PIG00-11115, PIG00-11116. Each pack includes one barrier transmitter, receiver collar not included.