Carabiner Shapes Explained
Pear (HMS), asymmetric D, oval, and symmetric D. When to use each shape, pros and cons, and a quick decision tree.
Carabiner shape determines how loads distribute across the metal, where the rope sits in the basket, and how easy the carabiner is to clip and unclip. Most climbers learn one or two shapes (the pear-shape locker for belaying, the asymmetric D for everything else) — but understanding all four shapes helps you build a versatile, weight-efficient rack.
This page covers the four main carabiner shapes in detail, with a quick decision tree at the bottom for choosing the right shape per application. For the broader carabiner reference (gates, materials, kN ratings), see our carabiners explained guide.
Pear / HMS
Use for:
Belaying with a tube device or Munter hitch, rappelling on doubled ropes, anchor master points
Pros:
Wide rope-side basket holds the bulky knot of a Munter hitch and accommodates ropes carrying multiple wraps. Standard belay shape.
Cons:
Heavier and bulkier than D-shapes. Less efficient for general anchor work.
Examples:
Petzl Attache, Petzl William, Black Diamond RockLock, Mammut Bionic Mythos
Asymmetric D
Use for:
Racking gear, anchor connections, personal anchor systems (PAS), most general-purpose climbing applications
Pros:
Strong on the major axis (where load is concentrated), lighter than HMS, compact body, large gate opening for the size.
Cons:
Smaller rope-side basket — not ideal for Munter hitch belays.
Examples:
Petzl Am'D, Black Diamond Oz, Edelrid Pure Screw, DMM Phantom
Oval
Use for:
Aid climbing (where racks of pulleys hang from a single carabiner), big-wall hauling, racking gear that needs even loading
Pros:
Symmetric — gear loads consistently in either direction. Stable orientation. Strong.
Cons:
Heavier than D-shapes for the same strength. Smaller gate opening relative to body size.
Examples:
Petzl OK, Black Diamond Oval, DMM Ultra-O
D-shape (symmetric)
Use for:
Older quickdraws, budget gear, general utility
Pros:
Strong and reliable. Available cheaply.
Cons:
Largely superseded by asymmetric D for the same applications. Heavier than modern alternatives.
Examples:
Many budget brand carabiners, older Black Diamond and Petzl quickdraw biners
Quick Decision Tree
Match your use case to the right shape:
Belaying with a tube device or GriGri?
Pear/HMS — the wide basket handles the device cleanly.
Belaying with a Munter hitch (no device)?
Pear/HMS, mandatory. Other shapes can jam with the bulky knot.
Racking trad gear on your harness?
Asymmetric D — light, compact, strong.
Building an anchor master point?
Pear/HMS for the master point itself; asymmetric D for the connections to individual pieces.
Connecting your harness to a personal anchor?
Asymmetric D screw-lock or auto-lock — secure and compact.
Hauling with pulleys on a big wall?
Oval — symmetric loading keeps multiple pulleys oriented correctly.
Browse carabiners
Pick the right shape, then browse our reviewed carabiners by category.
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