Difference Between 26-229 & 26-121

Question

What is the difference between product 26-229 and 26-121.  Their measurements are pretty much the same except one is slightly longer.  The screw positions and the width on the edge are the same.  One measurement is not shown is the width of the triangular latch that springs out and locks on to the rail.  mine is about 1/4 of an inch.  Please advice.

Paul · Accepted Answer

The measurements of the holes are the same, the housing is shorter on the 26-121. The triangular latch that springs out is 1/2" for both.