Vacuum gauges are like any other piece of technological equipment; they change and evolve over time. One of the primary differences between a new and improved item such as a smartphone and a next-generation replacement vacuum gauge is the naming process. Where many companies can develop new technology, implant it into the new product and give it a name such as HOMETHEATRE X4, a variation of their brand and product name, vacuum gauge manufacturers often don't. Most of the time, digital vacuum gauges are referred to by product numbers and not specific names. Because of this, an upgraded version may be more difficult to determine. Examples of such upgrades that customers have inquired into in the past include: the upgrade from the 810-2, which is the 801w2 the 200p, which is now the 215v the 100w, which is now the Bullseye Precision Gauge Sometimes You Need a Little Help From Your Friends All of these changes can be confusing when it is time to order a new gauge! Also, when you go to make an order…you may not be able to find your beloved vacuum gauge. That is when you could use a little help! Your old gauge may have become obsolete and have been retired from our product lines. These changes could be based on the following reasons: older technology components are no longer available or not as accurate as newer technology. In other words, a gauge is only retired and replaced by an entirely new gauge if it has, in one way or another, become obsolete. Because of this, customers using gauges that have been retired sometimes question whether they need to succumb to an upgrade or not. The answer to this is maybe/maybe not. Unless your instrument is not functioning well for your needs or you need a vacuum gauge that offers better accuracy, you do not need to upgrade.