Complete Repair set: This 2 piece sprayer accessory set includes stainless steel plunger rod and full seal washers, providing all wear prone parts for 440 / 450 models, eliminating separate part sourcing Leakproof Seal Components: Features wear resistant polymer and fluororubber seals that withstand paint / thinner, maintaining tight pressure sealing to prevents leaks, pressure drops, or uneven sprayer patterns Extended Service Life: Metal construction with seals (resistant to swelling / cracking) and long wearing plunger rod reduces frequent disassembly, lowering maintenance costs over time Fit: enabling direct replacement without modification—quick installation ensures minimal downtime Resistant Plunger Rod: machined from stainless steel with smooth surfaces, resist paint, wear from reciprocating motion, and deformation while rust, Manufacturer: APGLSXY