3-inch Barrel

A 3" barrel lets a long focal length eyepiece use a field stop too large for a 2" barrel, so a large telescope can show its widest true field.

Our 3" eyepiece is the Explore Scientific 100° Series 30mm, argon-purged and waterproof. It needs a 3" focuser and will not fit a 2" one. See all our 100° eyepieces for 2" sizes.

Not sure which suits your scope? Our eyepiece buyer's guide covers magnification, exit pupil and eye relief.