Mud River Swagger Neoprene Lined Collar w/Nickle Hardware Max-4 Camo Small. This dog collar from the experts at Mud River features a unique neoprene lining for comfort a nylon exterior for durability and is outfitted with a heavy-duty buckle. Specifications for Mud River Swagger Neoprene Lined Collar: Manufacturer: Mud River Fabric/Material: Nylon Package Contents: Mud River Swagger Neoprene Lined Collar Mud River 18431: Swagger Neoprene Lined Collar w/Nickle Hardware Max-4 Camo Small