The yoke clamp base will fit rails in diameter from 0.625" to a maximum of 1.25". The 1" rubber ball is at a right angle to the plane of the mount; when connected to a rail, the ball sits parallel to the rail.
Mfr. Part#: RAM-B-201U
$12.14
Mfr. Part#: RAM-B-201-A-ALA1-KRU
$18.56
Mfr. Part#: RAM-B-101U-C
$28.77
Mfr. Part#: RAM-B-176-A-UN7U
$45.67
Mfr. Part#: RAM-B-138-UN8U
$48.62