This will be redundant to a lot of you...lots of posts during the "skirmish" yesterday, but I think it deserves a thread we can send other questions to. Marlex ell..soft street ell to fit between swing joint & bottom of sprinkler body. It's used not only to provide absolute adjustment of plumb and level, but, most importantly...the only part of a irrigation system designed to fail!!! The softness will take a rock break while keeping the barbs or sch in swing joints intact, as well as the spinkler body. A "easy-out" can extract the Marlex, providing a cost effective repair. The cost is minimal (like 10" & standard valve boxes) compared to the labor to repair. A colleague on this site had problems with cheep Marlex ells, but I've not w/Spears or Lasco. When heads are spotted along driveways, we "sleeve" the heads with 6" abs pipe, notched on the bottom & filled around the head with pea gravel, tho we've had them get hammered too! Marlex are not to be used on mainline because of the softness. One of those dinky things that make our trade easy.