A crop, sometimes called a riding crop or hunting crop, is a short type of whip without a lash, used in horse riding, part of the family of tools known as horse whips.
A crop usually consists of a long shaft of fiberglass or cane or which is covered in leather, fabric, or similar material. The rod of a crop thickens at one end to form a handle, and terminates in a thin, flexible tress such as wound cord or a leather tongue. The thin end is intended to make contact with the horse. The handle may have a loop of leather to help secure the grip.
The length of a crop is designed to allow enough leverage for it to be accelerated rapidly with a controlled flick of the wrist without causing the rider balancing problems. Thus, a true crop is relatively short.
The term "whip" is a more common term that includes both riding crops as well as longer types of horse whips used for both riding and ground work. A whip is a little slower than a crop, mostly due to having slightly greater length and flexibility.
Crops are designed to back up the natural aids (leg, seat and voice) of a rider.
The riding crop is still widely seen as the traditional symbol of dominance in BDSM activities. Its material is the only obvious link with the (stereotypical) leather fetish in that scene.