In such instances, just a ‘flip-flop’ variety of bottle caps could be ample. But, if the contents within the bottle are used for a longer duration, then a threaded number of bottle caps could be required. But, such a superior number of plastic is probably not required for bottles containing engine oil and so forth. Relying on the tip use of the cap, the producer would determine the kind or variety of plastic to be used. For example, if the bottle’s contents are for single-use, then a threaded kind of cap will not be required. These caps are manufactured to the specific want of the client. Plastic caps can be found in numerous models and shapes.