RA Motor Drive for Twinstar 6" and 4.5" Reflector Telescopes with EQ Mount Compatible with the Twinstar AstroQuest 6" and AstroVenture 4.5" telescopes Easy to attach to your telescope mount Drive rotates your mount automatically keeping objects in view as the earth rotates Has a variable speed control to speed up or slow down the right ascension tracking speed Step-by-step Color Photo Online Assembly Guide