What are trailer hitch couplings and What types should I buy

Shocker 30K Gooseneck Air Hitch & 9 Offset 2-5/16 Coupler for Featherlite Trailer - 4RND AnglePin, 2-5/16Ball9OffsetCoupler

Type 'B' Bicycle Bike Trailer Coupler / Hitch Connector Sturdy, 1 Unit - Fry's Food Stores

Coupler Components

Many Kinds Of Trailer Couplers Competitive Price

METOWARE Keyed Alike Trailer Hitch Receiver& Coupler Lock Kit, 5/8 inch Dia Pin Lock, 1/4 Dia 2-1/2 inch Trailer Coupler Lock

Security Nut and Bolt Kit - Mega Hitch Lock

RINGFEDER® trailer coupling RF45 A/B, Couplings

Couplers for tow vehicles & trailers ain't sexy but necessary…

The Different Types of Trailer Hitches

Understanding Trailer Couplers: A Guide for Safe and Effective Towing

How to couple and uncouple a tractor-trailer as a CDL driver

Bicycle Trailer Coupler Attachment Bike Trailer Hitch Replacement Black