Poster title: A gravitationally lensed Lyman Alpha Nebula detected by VLT/MUSE IFU showing high emission escape fraction Poster abstract: We present a faint gravitationally lensed extended Lyman alpha nebula discovered at z=3.217 behind Hubble Frontier Field cluster MACS-J0416. By using a gravitational lens model, we constrain the properties of on one of the faintest extended system with L(lya) ~ 2×10^42 erg s-1, scale of ~ 20 kpc. In our result in reconstructed source plane in lensing model, f_esc is closer to 100%.