... glass ground joints made of borosilicate 3.3 pyrex male and female clear, blue, green, yellow, amber, pink, purple, red Ground glass joints of borosilicate 3.3 pyrex ... , and with ground glass joints may be rapidly ... ground glass joints are hollow on the inside and open at the ends, except for stoppers.Joint types: Conically tapered jointsBall-and-socket joints pyrex borosilicate glass ground joints ...