TEK-AD Tek Series 1.0 E-Collar Module - This industry-first combination of remote training and GPS tracking allows you to add dogs to your TEK 1.0 GPS+E-Collar system. The GPS and E-collars come as separate, compact modules that fit together on a single collar strap. All components feature SportDOG Brand's DRYTEK design, so they are waterproof and submersible up to 25 feet. Easily sync this collar to your TEK Series 1.0 Handheld Device to gain tracking and training abilities on up to 12 dogs! (12 separate collars required). This collar unit is only compatible with the TEK Series 1.0.