(4) #40-118-2 housing brackets with 5/8 holes for greater strength. The laser link features (4) 17 1/2″ Long Heavy duty, 1″x.156″ wall links. Links are direct threaded 3/4-16 left hand on one end 3/4-16 right hand on the other and feature oversize hex nuts for quick, easy adjustments. Each laser link comes complete with grade 8 hardware. SW insists that only chrome-moly rod ends be used with any 4-link system. Rod ends jam nuts not included.