Howard Leight Fendall Pure Flow 1000/ Fendall 2000 Tamper Seal. It is made out of a proprietary material that will easily rip when the unit is tampered with. Note the label with backing measures 6 1/4in x 2 1/4in and the label without the backing measures 6 7/8in x 2 7/8in. Specifications for Howard Leight Fendall Pure Flow 1000/Fendall 2000 Tamper Seal: Manufacturer: Howard Leight Size: One Size Gender: Unisex Package Contents: Howard Leight Fendall Pure Flow 1000/Fendall 2000 Tamper Seal Howard Leight 32-001017-0000: Fendall Pure Flow 1000/ Fendall 2000 Tamper Seal