Geophone keyway tee protective casing

A protective casing for a three-way electrical connection comprises a cover and two lower pieces. Each lower piece preferably includes a protruding key and a key slot. The two lower pieces mate with one another with the protruding key of each lower piece engaging the key slot of the other lower piece. The keys and slots generally extend a length of the lower pieces and thus mating the lower pieces together includes engaging the keys and slots and sliding one lower piece along an axis relative to the other lower piece. Preferably, the lower pieces are substantially identical. In contrast to conventional tee connection casings, the lower pieces of the preferred embodiment can be mated together without disconnecting any conductors from the three-way electrical connection. Similarly, the protective casing can be removed and replaced with a new casing without disconnecting any electrical connections.