Easy to install: simply screw into the harp and place the lampshade on top. fits standard finials and harps Riser length does not include threads 1 1/2" unfinished BRASS finial risers to raise lamp shade. These have standard threaded finial hole (1/4-27 thread) at bottom and standard finial thread at top (1/4-27 thread). HEIGHT DOES NOT INCLUDE THREADS AT THE TOP.