We present the design of the UV-VIS arm of SOXS which is being designed and built at the Weizmann Institute of Science astronomical instrumentation lab. Son Of X-Shooter (SOXS) is a new medium resolution spectrograph designed for the ESO 3.58 m New Technology Telescope (NTT). SOXS is designed to cover the entire band from 350-1800 nm with high throughput at a resolution of λ/Δλ~4500 (for 1” slit). As the name implies, SOXS was designed based on the successful 4-C design of X-Shooter. However the classical 4-C design uses a cross-dispersed echelle grating which is a source of significant throughput losses. Our Multi-Imaging Transient Spectrograph (MITS) splits the spectral band into four ~120 nm sub-bands. This allows the use of high efficiency ion-etched gratings which are each optimized for a narrow band, and are used at first order (m=1). As a result our design is estimated to increase the throughput to >50% (a 50-100% improvement over the classical design) while maintaining similar spectral resolution. All four ​sub-bands are then re-imaged onto a single 2k by 4k detector. We present the design​, ​resolution, throughput and image quality of MITS and discuss optical and mechanical considerations​. The instrument project went through the Preliminary Design Review in 2017 and is currently in the Final Design Phase (FDR in July 2018).