Comparison : Item # 10806, 1 1/4" with pipe nipple
Item # 21733, 1 1/4" with pipe nipple for contractor series
Item # 21734, Coupling, CFP-4C w/nipple
Item # 21735, Coupling, CFP-6C w/nipple
Item # 07715, 1 1/2" w/o pipe nipple