This new 1.35 kg (3 lb) counterweight is designed for SkyTracker Pro and SkyGuider pro counterweight package (#3324), as well as other iOptron mounts, which include: SkyGuider Pro SkyGuider CubePro Cube-A (Dual AltAz/EQ mounts)* Cube-G* Cube-E* CEM25/ZEQ25 iEQ30 Pro/iEQ30 CEM40/CEM40EC MiniTower/ II / Pro AZ Mount Pro * It works together with CW shaft (#8607) for Cube-A/G/E.