Compact brass oil level sight glass with 3/8' BSPP male thread, hex head, and 5 bar pressure rating. Designed for direct visual monitoring of lubricant level in air compressor crankcases, gearboxes and similar machines, it lets you confirm oil presence quickly and reliably without shutdown or disassembly. Why you need it Instant visual check: See oil level at a glance to prevent running equipment dry and reduce risk of damage. Saves time: Eliminates unnecessary disassembly and frequent manual checks, lowering downtime and maintenance effort. Durable construction: Brass body resists corrosion and provides long service life in typical lubrication environments. Simple fit: 3/8' BSPP male thread and hex head allow fast installation with standard tools into compatible ports. Key attributes Thread type: Metric BSPP (male), 3/8' Material: Brass body with integrated sight window Function: Oil level sight glass / window for lubricant monitoring Pressure rating: 5 bar Head style: Hex head for wrench installation Typical applications: Air compressor crankcases, gearboxes, small industrial machinery Typical use cases Air compressor gearbox: Install in the crankcase or gearbox housing to monitor lubricant level during operation and maintenance checks. Industrial gearboxes and reducers: Provide an accessible visual oil level reference on production equipment to help prevent inadequate lubrication. Small engines and pumps: Add a compact sight window for routine inspections without disassembly. Installation and operation Fits into ports that accept a 3/8' BSPP male connection; tighten using the hex head with appropriate torque for a secure fit. Designed for oil and common lubricants used in compressors and gearboxes at or below the 5 bar pressure rating. Inspect the sight window regularly for clarity and if damaged to maintain accurate level readings. What this part delivers Clear, reliable oil level indication for preventive maintenance Robust brass construction for longterm use in lubrication systems Straightforward installation into compatible 3/8' BSPP female ports Compatible systems Air compressors, gearboxes, small industrial machines and other equipment that accept a 3/8' BSPP male oil sight glass with a maximum operating pressure of 5 bar.