Caulkin

[1][2] The term may also refer to traction devices screwed into the bottom of a horseshoe, also commonly called shoe studs or screw-in calks.

Caulkins or studs improve a horse's balance and grip over uneven or slippery terrain, allowing the animal to move better and jump more confidently in poor footing.

Traditionally, the prongs of an elongated horseshoe (commonly not more than 1+3⁄4 inches or 44 millimetres) have tips bent at an acute angle opposite to the surface attached to the horses' hoof.

That caulk/wedge horseshoe is a traditional British hunting shoe, and it has been used to provide the horse with a sure-footed grip when working at a fast pace over uneven ground.

[3] The shapes of the caulkin and the wedge have been designed to provide hoof traction, meanwhile ensuring the horse's safety is not compromised.

Screw-in calks or studs are popular in sport competition because they can be changed to adapt to different terrain.

A hoof pick or horseshoe nail can help remove the plug prior to insertion of a screw-in stud.

When stabled, animals wearing caulkins need extra bedding to avoid abrasion when lying down and for protection while moving about in a confined area.

Most riders place smaller studs on the front feet, because the horse's hind legs are stronger and generally require more traction.