Abstract: A plurality of resiliently yieldable, molded plastic links, each having complimentary ball and socket portions at opposed longitudinal ends, are snap-locked together to form a closed loop pet collar. One of the interlocked links is adjustable to release when subjected to a threshold collar tension, to protect the pet should the collar catch on some obstruction. For this purpose, the adjustable link includes an adjusting screw threadedly disposed in a longitudinal bore of the link and accessible for screwdriver adjustment through the socket portion thereof, and having an end extending centrally and longitudinally into the ball portion of the link. The ball portion of the link is slotted to modify the compressibility thereof and the internally mounted screw is longitudinally positionable to vary the ball portion compressibility and thus the threshold force required to release this link from the socket portion of an adjoining link.