Comparison : Item # 15P, Replacement Elements - up to 300 SCFM flow
Item # 14P, Replacement Elements - up to 300 SCFM flow
Item # 19P, Replacement Elements - up to 300 SCFM flow
Item # 18P, Replacement Elements - up to 300 SCFM flow
Item # 31P, Replacement Elements - up to 300 SCFM flow