Bisley Eyepiece Extensions
By cupping the eye and obliterating exterior light this Scope accessory forces the eye to adjust to obtain the maximum amount of light through the scope. Test have resulted in extended use of twilight by up to 15 minutes. Suitable for spectacle wearers and most scopes.... (more)
These scope extension eyepieces come in 60mm or 90mm in length and will fit most 1" scopes.... (more)