What it is The Hareline PEAK D-Arm is a fly-tying handle tool with a horizontal handle orientation. It’s built with a durable construction and an ergonomic grip that’s meant to reduce hand and wrist fatigue during long sessions at the vise. What to tie with it You use it to hold fly-tying materials while you work, especially when you want better control and leverage. The horizontal grip is handy when you’re putting tension on materials and when you’re doing a lot of rotary-style wrapping and positioning at the hook. Flies and the fish they're for This style of handle is commonly put to work when tying bigger, torque-heavy patterns like saltwater bugs where you’re pulling hard on materials and want steadier control. Those flies are typically tied for species like redfish, snook, striped bass, and tarpon in the salt, and for largemouth and smallmouth bass in freshwater. How it compares Compared with standard handle designs, the horizontal grip is more ergonomic for tyers who don’t like a vertical handle, and it can make rotary tying motions feel more natural.