Seating the Gasket

I found the insulated stainless steel flask resting uncapped on the dining counter. Beside its rim, a black silicone gasket had slipped out of the lid, resting half-pinched against the threading. I planted my bare feet firmly on the cool quartz surface and took the flexible ring between my fingers. Testing its elasticity with a light, controlled pull, I aligned the inner lip against the cap's milled circular groove. Pressing down incrementally with both thumbs, I guided the silicone into the channel until it seated flush without twisting. Threading the lid back on, the seal met the rim with quiet, airtight resistance.