We are lucky to have two of the most knowledgable golf gearheads in our Golf Digest family. And they are sharing their golf equipment knowledge with you. Golf Digest’s US-based equipment editors, Mike Stachura and E. Michael Johnson, have covered the golf equipment business for decades, and there are few who know the equipment industry better. We’ve asked them to answer your questions in a weekly equipment round-up. Tweet them any equipment questions you have, and they might answer your questions next week. (Click here or hereto ask them a question.)

What are the things you look for when buying a used set of irons? —@solson503

You should approach buying a used set of clubs much like you would when buying a used car. First you want to find a reputable dealer, then you want to make sure you’re getting exactly what you’re paying for. So, what makes a reputable dealer? Basically, make sure it’s an outfit either with a great reputation in the area of used clubs or one you personally trust. Some of the equipment companies have pre-owned portions of their websites, too, which is trustworthy. eBay? Now you’re in risky territory when it comes to private sellers.

As for getting what you pay for, part of that means knowing what it is you’re looking for. These clubs might be stock, but consider that they might have been fit to a person with specific specs. If you have a specific fit you need (and we all do), then make sure you’re getting clubs that will work for you. If you’re a half-inch over and 1 degree upright, see if you find out the specs and if they’re a match. Otherwise you have some alterations to make after the purchase.

Finally, condition is important. If the grips are shot, you’re going to spend another $50 to $100 re-gripping the clubs. That’s just something to consider. Like buying a used car with old tires. Also, make sure the shaft flex is a match, too. And don’t forget, sometimes you can trade in old clubs and get a credit towards your purchase of used clubs, too. That’s why it can help going through a reputable site or manufacturer.

Is there an app that will track my shots in a backyard hitting cage? Distance, carry, spin, speed. Don’t have hundreds to spend. —@craig_vee

We can certainly appreciate not having big bucks to spend on a launch monitor or even several of the decent apps that are pretty pricey or require some additional hardware. There is one app available called Shot Vision that seems to fit what you’re after. Full disclosure: We’ve never tried it, but its website lists 121 ratings with an average score of 4 out of 5. The website says the app can calculate ball speed, launch angle, spin rate, carry and total distance, as well as the height of the ball flight. It also notes that club speed, dynamic loft and attack angle has been added in its latest version. It can be used indoors or outdoors. Pretty nifty stuff. If you want to get more involved, there is a Pro subscription at a cost. However with most things, you get what you pay for. Some users reported distance and other numbers that were way off. However, the support team for the app appears to be helpful. As for compatibility, Shot Vision can be used with iOS 11.1 or later, iPhone, iPad and iPod Touch.