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Recently a remarkable low surface brightness galaxy comma NGC5846-UDG1 comma was discovered in archival ground-based CFHT data. The galaxy has a low stellar mass (virgul10elev8 solar masses) comma a large size (r_e=1.8 kpc) comma and an unprecedented number of compact sources that resemble globular clusters. Keck spectroscopy confirms the association of the globular clusters and the diffuse lightdoublePoint they are at a common radial velocity of virgul2000 km-s comma close to the group velocity of virgul1900 km-s. Based on the current ground-based imaging and spectroscopic data the galaxy might have up to 30% of its light in the form of globular clusters comma significantly higher than any other galaxy known to date. Taking diffusion of low mass clusters into account comma it is possible that the galaxy consisted solely of virgul100 globular clusters when it formed. Here we request 2 WFC3-UVIS orbits to study this extreme galaxy along with its unusual globular cluster system. With WFC3-UVIS we will measure the sizes comma colors comma ellipticities and luminosity function of the clusters. These properties will be compared to the globular cluster systems of other galaxies (and in particular other Ultra Diffuse Galaxies) comma to determine whether NGC5846-UDG1.s globular clusters have similarities to those in other galaxies or represent something entirely new. We will also use the data to better determine the structure and morphology of this enigmatic galaxy in order to put further constraints on its dynamical state.