American Lube C38121-801 1000 Series Filter/Regulator/LubricatorAmerican Lube C38121 801 Filters, Regulators, Lubricators, And Piggybacks Can Be Combined Together To Form Combinations. They Are Typically Strung Together In The F+R+L Arrangement (Three Piece Combo) And F R+L (Two Piece Combo) Arrangement, Although Other Configurations Are Also Used Depending On Application Needs. Aro Flo Combination Frls Are Easily Assembled Using Modular Spacer Kits. 1000 Series Filter Regulator Lubricator : Auto Drain