SIEMENS brand COHERENCE RT Therapist versions RTT MR1.5, RTT 2.1/2.1A and RTT 2.2/ 2.2B; Software release for COHERENCE Therapist 2.3 for Primus and Oncor Linear Accelerators; || Model: || Primeview 3i 2.0, Part No. 8139847, || Current R630; || Product Usage: || The intended use of the SIEMENS branded ONCOR and PRIMUS family of linear accelerator systems is to deliver X-ray photon and electron radiation for the therapeutic treatment of cancer.