The PAC F8C mini dog containment collar suits all PAC invisible dog fences. It allows you to run a small F8C collar for small dogs and standard F6C collar for larger dogs in the same PAC fence system. This F8C collar is designed for small dogs and cats with low to high 4 auto levels of output. It is fully waterproof and rechargeable. The collar is made of lexan plastic which is same as bulletproof material.