Stand behind a lat pulldown machine. Step back so your lats can get a stretch when your arms are extended. Start these with your lats stretched and shoulder blades elevated and protracted. Initiate the pull by pulling your shoulder blades down your back and together arch your chest and stomach out to the handle really hard and drive your elbows back as hard as you can. Think of it this way, arms out; roll over, stretch. Pulldown; arch into it, elbows back.
These are usually done on our dynamic days because they are relatively less taxing. Sets and reps are usually 3-6 x 10-20. If you get in the lower rep ranges it's hard to keep yourself anchored.
The mag handles are great for putting more stress on your lats and less on your biceps. I would highly recommend them for rehab from a bicep tear , working with pitchers or any population looking to reduce elbow stress.