My original Cap has aged cracked rubber, but the threaded cap (original remington)
super tighten it by hand and threads on black cap "Stop" on male threads,,,and do not slip. This cap under light twisting thumb and for finger pressure slips on male threads. I guess just another piece of imported Chinese low quality. I will try to remove rubber bulb from this new one and place it into my original "Good" thread cap. I'd keep away from this kind of import Quality.