Large opening R.A.M. vials are specially designed for compatibility with robotic arm autosamplers. The large opening/mouth is suitable when autosampling with a large gauge.
Almost all R.A.M. vials are 12 x 32 mm with a 9mm opening. Invariably composed of Type I boroslicate glass for heat and shock resistance, R.A.M. vials do differ in glass type (clear or amber) and by choice of graduation marking spots (with or without).
Unlike (overpriced!) proprietary vials, J.G. Finneran's R.A.M. vials are compatible with a wide array of autosamplers. For maximum convenience and security, JGF's R.A.M. vials are screw-threaded (rather than crimp-topped).