The LaVision Light Sheet UltraMicroscope is a light sheet fluorescence microscope (also known as SPIM - Selective Plane Illumination Microscopy) designed for fast, gentle, and high-resolution 3D imaging of large biological samples, including cleared tissues and whole organs. It employs a thin sheet of laser light to illuminate only the focal plane, significantly reducing phototoxicity and photobleaching compared to traditional widefield or confocal methods. Key features include dual-sided illumination for homogeneous light delivery and reduced shadowing artifacts, a wide range of excitation wavelengths (e.g., 460-800nm from a supercontinuum laser), and high-speed sCMOS cameras for rapid data acquisition. It supports imaging of samples ranging from micrometers to centimeters, providing cellular resolution for large specimens and enabling in vivo imaging at room temperature.