Which of the following instruments is classified strictly for needle holding?

Mayo-Hegar needle holders are specifically designed for grasping and holding needles securely during suturing procedures. Their structure includes a locking mechanism that allows for a strong grip on the needle without slipping, ensuring precision when stitching tissues together. This feature is crucial for veterinarians and veterinary nurses who often need to handle various sizes of needles for surgical procedures.

In contrast, Olsen-Hegar needle holders serve a dual purpose by also incorporating a cutting mechanism, making them versatile but not strictly classified for needle holding alone. Rampley sponge holding forceps are primarily designed for holding sponges and gauze, rather than needles. Spencer stitch scissors are specifically made for cutting sutures or tissue, not for holding needles. Thus, Mayo-Hegar needle holders stand out as the specialized instrument strictly used for the purpose of holding needles.