The following commentary comes from an independent investor or market observer as part of TheStreet's guest contributor program, which is separate from the company's news coverage.NEW YORK ( ETF Expert) --There are four exchange-traded vehicles with sufficient volume that a master limited partnership (MLP) enthusiast should consider. More specifically, for those investors who do not wish to pick individual securities, there are several diversified MLP products offering the possibility of capital appreciation and the certainty of a solid income stream. First, a quick primer on energy pipeline partnerships. Energy MLPs typically own the pipelines that transport crude oil and natural gas throughout the country. Although the underlying commodity can affect their price, the more significant driver tends to be genuine supply and demand. Most importantly, investors often buy MLP shares as "income producing properties," since the distributions often range from 5% to 7%. There are many reasons for investors to avoid individual MLPs, from the tax headaches to the difficulty in identifying the best prospect. Yet the reasons to gain MLP exposure via an exchange-traded vehicle are increasing by the minute. 1. Technical Uptrend. A number of stock ETFs may have risen above a shorter-term, 50-day moving average. Yet very few have recovered a longer-term 200-day trendline. UBS MLP Alerian Infrastructure ( MLPI) has done exactly that. What's more, it boasts "higher lows" since the month of August.