A puncture in your sleeping pad means a flat, cold night, and most field patches lift the moment you re-inflate. The Airlock Patch is engineered for TPU substrates specifically: a transparent 0.16 mm TPU film fused to a pressure-sensitive adhesive that bonds TPU to TPU. Edges stay sealed through inflation and deflation cycles where generic patches fail. 0.39 g per patch, 8 per pack. The two-piece waxed paper liner lets you peel half, align, press, and roll away the second half cleanly. Use immediately; full bond strength at roughly 4 hours. See Patch Science: Threadlock vs. Airlock for the material rationale and keeping inflatable gear alive for trail maintenance. For woven fabric tears, use the Threadlock Patch. Both ship inside the Repair Spool and First Aid & Repair Kit.