As good as it gets! This one comes with a back plate that bolts to the back of a synta/Celestron 6" refractors but this focuser can also be mounted on any other OTA with a flat back plate too(plate is removable). about 5" of travel and has the 500:1 fine focus option. Three collimation screws. Comes with 2" adapter. This focuser isn't made anymore. ***SALE PENDING*** shipped insured by UPS in the US.