Yolk muscle pair is

Yoke muscles (contralateral synergists)refers to the pair of muscles (one from each eye) which contract simultaneously during version movements. For example, right lateral rectus and left medial rectus act as yoke muscles for dextroversion movements. Other pairs of yoke muscles are: right MR and left LR, right LR and left MR, right SR and left IO, right and left SO, right SO and left IR, and right IO and Left SRRefer: AK Khurana Comprehensive Ophthalmology, 6th edition, pg no. 339