Intended for nighttime observation of emission and planetary nebulae, especially the Veil Nebula NGC 6992, the O-III Filter from Explore Scientific is compatible with telescopes featuring a 1.25"-diameter eyepiece. This filter is designed to only pass the two lines of ionized oxygen, between a 483-511nm range with 96.7% transmittance, in order to better discern fine details and boost the contrast of the specific emission lines for clearer viewing.