The Compact, Lightweight Micro-iDT Training Collar! The rugged micro-sized collar unit and transmitter fit in the palm of your hand. The comfortable waterproof collar fits small to large dogs. The Micro-iDT Series represent the absolute latest technological advancement in the Electronic Dog Training World. It offers Maxx-Range, the industry's only internal FM radio frequency antenna woven in the collar. With up to a 900 yard range, they are perfect for field or household use. The Micro-iDT Series collars feature Sixteen levels of stimulation intensity, with an easy 'no look' clicking stimulation dial. Easy one hand held operation allows for maximum control and safety. 900 Yard Range Supports up to 4 dogs (Add-On collars sold separately 16 Levels of Intensity adjusted from the Transmitter Positive vibration available Rechargeable Ni-MH battery system in the collar