NPS - 'Nominal Pipe Size' and DN - 'Diametre Nominal'
Brass Pipe Hex Nipple Fitting Quick Adapter 1/8" 1/4" 3/8" 1/2" 3/4" 1" BSP Male Thread Water, oil and gas Connector - AliExpress
Find your way between inches and millimeters
Buy Visiaro Soft Copper Tube, 25ft, Outer Dia 1/4''
6.4 mm (1/4 Inch) Insulation Tube 9mm Thick | Air Conditioner & Home Appliances Sales / Service
Hromee Air Line Tubing Kit, 1/4 Inch (6.35MM) OD x 32.8 Feet Polyurethane PU Tube and Push to Connect Fittings, 14 PCS Compressed Pipe and Accessories Kit: Amazon.com: Industrial & Scientific
METTUBE 1/4 inch (OD- 6.4 mm) Soft Copper Pipe 15 Meters (50 Feet) for Air Conditioners 50 mm Plumbing Pipe Price in India - Buy METTUBE 1/4 inch (OD- 6.4 mm) Soft
HYDROMAXX 1-1/4 in. Dia x 25 ft. MM Sizing Black Non Kink, Corrugated, Flexible PVC Pond Tubing 1302114025 - The Home Depot