Keys Fitness ST-IB Owner's Manual page 14

Assembly
Step 16
Attach a curl bumper (66) to curl bar (31) using a M4X16mm screw (57).
Attach the curl bar (31) to the leg lever (18) and secure with the curl bar pin (28). Next,
attach the tether on the curl bar pin (28) to the leg lever (18) using a M4X16mm screw (57).
Step 17
Tighten all hardware from the previous steps using the appropriate tools.
31
66
57
18
57
28
14
Figure 16