SMALLRIG 15mm Railblock Vertical Quick Easy Adjustment Rod Clamp Mount for 15mm Camera Baseplates - 1519 SMALLRIG 15mm Railblock 1519 used with 15mm Camera Baseplates with vertical 15mm rods to provide vertical quick, easy adjustments. Height Adjustment.With this 15mm Railblock Vertical Rod Clamp added to pair of 15mm short raiser rods (Search "SmallRig short rods"), it can acheive flexibility of raising up and down your matte box,FOLLOW FOCUS,or,lens holder. The ratcheting knobs allow easy adjustment of the rods in tight places. Note:vertical 15mm short rods are not included. (Search Smallrig 1515,Smallrig 1523, Smallrig 1590 for vertical 15mm short rods ) Material: Aluminum Alloy