What it is and what it fits
The Siemens 7ME3960-0SM50 is a mounting strap for dedicated transducers on the SITRANS FS220 ultrasonic flowmeter, sized for pipe diameters DN1500 to DN2100 (Leg. Nr. 1012MS-5). If you're retrofitting or replacing the strap on a large-bore ultrasonic installation, this is the factory strap for that transducer set.
Compliance note
The 7ME3960-0SM50 is not RoHS-compliant. If your site or jurisdiction requires RoHS compliance for flowmeter mounting hardware, factor that in. REACH Article 33 candidate list information is available from the manufacturer. Export Control Regulations are AL: N / ECCN: 9N9999, no special licensing required for most destinations.