Comparison : Item # 4011-17, Flask, Round Bottom, Angled Two Neck, with GL Threads, 500mL, GL-25
Item # 4011-18, Flask, Round Bottom, Angled Two Neck, with GL Threads, 500mL, GL-32
Item # 4011-20, Flask, Round Bottom, Angled Two Neck, with GL Threads, 500mL, GL-45
Item # 4011-22, Flask, Round Bottom, Angled Two Neck, with GL Threads, 1000mL, GL-32
Item # 4011-24, Flask, Round Bottom, Angled Two Neck, with GL Threads, 1000mL, GL-45