Abstract: An elongated housing is provided including opposite ends and an outwardly concave longitudinal side extending between the opposite ends of the housing. The housing includes openings formed through the aforementioned concave longitudinal side thereof at points spaced longitudinally along the housing and structure is provided for securing the housing on a flexible animal collar with the concave side of the housing opposing and extending lengthwise along the outer side of the collar and that portion of the collar extending between the ends of the housing being arcuate and conforming to the arc of the longitudinal side of the housing.