The link at the bottom is a PDF of some Hungarian regulations describing how to certify scales. They mention this type of sealing. It is a wire run through two screwholes and sealed, so the instrument/device cannot be opened up or tampered with without breaking the seal.

I think these are simply called "wire seals" in English.

"Tamper detection
The split configuration of Gemini PLC meters significantly reduces the risk of tampering, especially considering that the meter is installed in a remote, secure location. The meter is also mechanically sealed against tampering through the use of a factory-sealed screw plugs on the rear of the meter, and a utility-sealed wire seal on the front of the meter. The use of these mechanical seals ensures that there are visible signs of tampering if unauthorised entry is attempted."
This is from here:
http://www.za.landisgyr.com/za/prepay/prepay_metsingle_gempl...