50 mm thrust bearing for mast diameters up to 50 mm, ball bearing design, with 4 installation bolts. The bearing can be used without a mast platform with guys (see drawing); the required support ring to attach the guys are supplied with the GS-050. Small protective metal pieces prevent any damage to the mast when fixing the installation nuts. Mechanical installation as with the model GS-680U, however, mast diameter only 66 mm. Does not fit the rotator platforms!