Rulers are a challenging item to merchandise in any high-visibility, space-efficient way. If you insist upon a Scan Hook, one with vertically oriented Label Holders would save space and allow a tighter display even though difficult to read. One good thing about this display is the use of Metal Backplate Straight-Entry Pegboard Hooks. CLICK thumbnail for an alternate view.

For another narrow item category, SEE…
Slim Jim on a Pegboard Hook
Sasquatch vs Slim Jim

For One-Hole (a.k.a. One-Lug) Hooks, SEE…
Perfect Use of One-Hole Hooks
One-Hole Hooks Compared” and
One-Hole Hooks on Display

For other other density-increasing arrangements SEE…
Hook Mis-align Increases Sales
Hook Stagger Violates Convention” and
Erratic Hooks Tighten Display.”

For vertical label holders as a space saving device SEE…
Rotated Toothbrush Label Holders” and less well-done
B/P Anchors Toothbrushes
Label Orientation Alternates

Also compare label holder size and use at…
Label Size vs Display Density
Rulers Sold On Hooks
Short Sheeted 3/4″ Deep Label Holders
Buy-One Get-One Flip-Front Selling Tool
How to Make a Flip Front Sign Holder
Narrow vs. Wide Label Holders.”

For Straight-Entry Hook basics start with…
Straight-Entry Hooking Benefits
One-piece vs Two-piece Straight Entry Hooks
Straight-Entry Marquee Items