Two Quickfit standard ground joint equipped test-tubes. The joint size is 24/20 and fits both 24/29 and 24/40 apparatus and adapters. These tubes are approximately 20cm long and have a fairly heavy wall and are made from Pyrex borosilicate glass. They are suitable for heats up to about 350C and are non-reactive with most chemicals. These items are a mixture of new & used items, all of which are in great physical condition, there are no marks, chips or cracks.