Explore Scientific 5.5mm 100 degree Series Argon-Purged Waterproof Eyepiece EPWP10055-01. 5mm 100-Degree Series Argon-Purged Waterproof Eyepiece. The Explore Scientific 5.5mm 100 Series Hyper-Wide Argon-Purged Eyepiece features a field of view that is...