Market Forge 08-6399 Lowest Level Probe # 44-1259, Used With, Probe Plate 4 3/16″ Dia., L1 L2 H Probe Holes Are 3/8″ Fpt, Probe Plate Gasket 4-1/4″ Dia 2 11/16″ Id Red Silicone, 1 1/4″ Mt Hole Ctrs., For 2 Probe Systems Before 1999 And 3 Probe Units., Used With Probe Plate # 26-2484, Used With Low Level Probe # 44-1260, Used With Fill Probe # 44-1140