The Apex Instruments Standard Method 5 Heated Probe features a 1-inch diameter sheath constructed from corrosion-resistant stainless steel, modular 3/8-inch pitot tip, 1/4-inch stainless steel quick connects, type-K thermocouples for stack and probe temperature, probe heater, orsat line, and a small parts package. Standard lengths are 3 feet to 16 feet. Longer lengths and custom orders are available by request. Probes are ordered according to nominal (liner length). Effective length is one foot less than the nominal length. Order probe liners separately.