PBC Linear SRAM16 0900 SL Linear Metric Shaft Assembly, 16 mm Shaft Dia, 900 mm Lg, Steel 6047121.002 and an explosion proof loudspeaker that and an explosion proof loudspeaker that also functions as the microphone Surface Hardness 70 RC Finish Ceramic Coated Mounting Hole from Shaft End 2 in Type Aluminum Rail Shaft System of Measurement Inch Rail End to Hole 4 in Shaft Material Aluminum Shaft Material Finish Ceramic Coated Support Rail Material Finish Ceramic Coated Shaft Hole Spacing 8 in Maximum Operating Temperature 400 Degrees F Shaft Drilling Pre Drilled Support Rail Material Aluminum Shaft End to Hole 4 in Minimum Operating Temperature 0 Degrees F Resistance Properties Corrosion Resistance Shaft Hardness RC 60 Compatible Series FrelonGOLD(R) Linear Plane Bearings and Pillow Blocks