Adapter has a standard taper outer joint at the top of the main tube for use with jointed thermometers. The 10/18 size is used with 10/18, 25mm immersion thermometers while the 10/30 is for use with CG-3506, 75mm immersion thermometers. Sidearm has a standard taper outer joint with main tube having an inner joint, both being the same size.