
1.25" Rack and pinion focuser found on most 4.5" Newtonians , 5.5" curved base, 42mm travel
FOC4.5 is a standard 1.25" rack&pinion focuser found on most commercial 4.5" telescopes.. It's got a curved base for 5.5" diameter, low focus of 3" and travel of 1.9". Great for ATM's, or use for replacement. Plastic construction.