Sparkler Envelopes are required for the mechanical stage of the Oil-Max Oil Filtration System. Envelopes should be changed out after every use. Replacement of the envelope is quick and easy.
Simply cut and replace.
Oil-Max Filtration Systems consists of 3 envelope sizes depending on the SOF System.

Small- 11"x11" (SOF 50 Model)
Medium- 14"x14" (SOF 90/SOF 150 Models)
Large- 17"x17" (SOF 250 Model)