The Redrock Micro microLink4 Straight allows two sets of 15mm rods to be attached in parallel with a DSLR camera rig.• The Redrock Micro Microlink4 Straight is necessary when you use a shoulder mount rig or a smaller body HDSLR• The spacing between all the 4 holes in the Redrock Micro Microlink4 Staright is 60mm from center to center  • The Redrock Micro Microlink4 Straight can be combined with the microShoulderMount or eyeSpy to balance a DSLR camera and to position the camera correctly at eye level