The AR-40X is for large FM-TV and compact communication antenna arrays up to 3 square feet wind load area. Dual 12 ball bearing race is exclusive to its class. Automatic position sensor never needs resetting.
The CD-45IIX handles 8.5 sq. feet mounted inside a tower, or 5 sq. ft. with mast adapter. Low temperature grease good to -30 F degrees. Bell rotator design gives total weather protection, dual 58 ball bearing race gives proven support.