Pratt's Safety Squeeze Bottles flexible spout dispenses fine stream from polyethylene bottle. Stainles steel ball check in nozzle prevents leakage in case of tipping. Nos. 4723F and 4724F have all stainless steel and polyethylene construction for safe, dependable leak-free service. Nos. 4726F and 4727F feature an aluminium nozzle and independent vacuum breaker in aluminium plug that keeps the dispensing tube filled with liquid.