The magnetic dog collar is made from a very durable poly-cotton interwoven cord-type material which is more than strong enough to be used with a lead. The collar contains a magnetic strip, 300 gauss in strength, which is north towards the dog's body. Available in 2 different colours. The Dog Collar will not effect implanted security chips. Recommended for aged pets, and those suffering from Rheumatic or Arthritic disorders.This product has a very Positive Customer Feedback.Yellow is DC-2