Fit for: These air spring bags are replacement for Peterbilt 379 trucks 29-03200, for Firestone W01-358-7036 and for Goodyear 1S5-186. Cross References: for Firestone W02-358-7036, W023587036, W02-3587036 for Goodyear 1S5-186 for Peterbilt 29-03200, 2903200, 2902454 Quantity: 2 piece in one set Features： – Direct replacement. Ready to use. -Mates with OE Air Lines -Designed for Comfort Suspension Notice： -These air suspension bags are aftermarket ones.  -Instruction is not included. Professional installation is recommended -Contact us please for whatever we can help. Hold up to 350 PSI – Test more than 28 million times 100% Air Tightness testing – Gives the driver more control of ride Built to strict quality control standards – Designed for Comfort Suspension Conditon: New