Manfrotto 061 is used to mount two Super Clamps back to back, parallel or at one of the following angles: 60ΒΊ, 120ΒΊ, 180ΒΊ etc. Manfrotto 061RA is used to mount two Super Clamps at right angles to each other or at the following angles: 30ΒΊ, 90ΒΊ, 150ΒΊ etc. Both do their job perfectly; Just make sure you have the right one for your needs. If you have both on hand, you can use a variety of angles.