System for detecting the strain and/or monitoring the condition of a reinforcing element of an elastomeric product with the elastomeric product with a product body which at least substantially comprises an elastomeric material, characterized in that the product body has at least in some portions at least one magnetostrictive body , preferably a ferromagnetic body , and wherein the product body has at least in some portions at least one reinforcing element , which is embedded in the product body , with an electromagnetic-acoustic (ultra)transducer , which is arranged at a distance from the elastomeric product and sufficiently close to the magnetostrictive body of the product body and is also designed to excite the magnetostrictive body by means of an electromagnetic alternating field to emit at least one first outgoing sound wave (W1), preferably at least one first outgoing ultrasound wave (W1), which completes a closed path through the magnetostrictive body of the product body , so that the dipoles of the magnetostrictive body of the product body are aligned alternately in opposite directions, and to detect inverse-magnetostrictively at least one first incoming sound wave (W1') at the magnetostrictive body , preferably a first incoming ultrasound wave (W1') at the magnetostrictive body , wherein the reinforcing element is at least in some portions arranged sufficiently close to the magnetostrictive body to receive the first outgoing sound wave (W1) from the magnetostrictive body and return it as a first incoming sound wave (W1') to the magnetostrictive body , and wherein a change in length of the magnetostrictive body of the product body can be determined from the first incoming sound wave (W1'). with the elastomeric product with a product body which at least substantially comprises an elastomeric material, characterized in that the product body has at least in some portions at least one magnetostrictive body , preferably a ferromagnetic body , and wherein the product body has at least in some portions at least one reinforcing element , which is embedded in the product body , with an electromagnetic-acoustic (ultra)transducer , which is arranged at a distance from the elastomeric product and sufficiently close to the magnetostrictive body of the product body and is also designed to excite the magnetostrictive body by means of an electromagnetic alternating field to emit at least one first outgoing sound wave (W1), preferably at least one first outgoing ultrasound wave (W1), which completes a closed path through the magnetostrictive body of the product body , so that the dipoles of the magnetostrictive body of the product body are aligned alternately in opposite directions, and to detect inverse-magnetostrictively at least one first incoming sound wave (W1') at the magnetostrictive body , preferably a first incoming ultrasound wave (W1') at the magnetostrictive body , wherein the reinforcing element is at least in some portions arranged sufficiently close to the magnetostrictive body to receive the first outgoing sound wave (W1) from the magnetostrictive body and return it as a first incoming sound wave (W1') to the magnetostrictive body , and wherein a change in length of the magnetostrictive body of the product body can be determined from the first incoming sound wave (W1'). <EOS>