SunStar Restrictor Plate (Required for Input Btu hr Conversion) Fits In:SIS SIU125 Size Gas Type Description AV12PCN TALLSID2 50 Size Gas Type Description AV12PCN 12” Natural Gas Polished Chrome Valve Kit AV12PCP 12” Liquid Propane Polished Chrome Valve Kit AV12PBN 12” Natural Gas Polished Brass Valve Kit AV12PBP 12” Liquid Propane Polished Brass Valve Kit AV17PCN 17” Natural Gas Polished Chrome Valve Kit AV17PCP 17” Liquid Propane Polished Chrome Valve Kit AV17PBN 17” Natural Gas Polished Brass Valve Kit AV17PBP 17” Liquid Propane Polished Brass Valve Kit Unwavering and steadfast The SunStar Gas Valve Kit is to be use with Gas Conversion Kit to convert Input Btu hr the 100 through 175 MBtu hr heaters cannot be converted to less than 100 MBtu hr