These are JWICK switches, manufactured by JWK. JWICK is the English name for Dongguan Jingweike (精微科) Electronic Technology Co., Ltd. JWICK Ultimate feature new molds and some special additives to the top and bottom housing materials that are designed to optimize the bottoming out and topping out sounds. JWICK Ultimate has deeper a.k.a. "thocky" sound profile compare to the regular one. It is very durable and good quality switch and at the same time, JWICK switches very affordable and budget friendly.