We compute the group of K 1 -zero-cycles on the second generalized involution variety for an algebra of degree 4 with symplectic involution. This description is given in terms of the group of multipliers of similitudes associated to the algebra with involution. Our method utilizes the framework of Chernousov and Merkurjev for computing K 1 -zero-cycles in terms of R-equivalence classes of prescribed algebraic groups. This gives a computation of K 1 -zero-cycles for some homogeneous varieties of type C 2 .where X (i) is the set of points of X of dimension i, K i are Quillen K-groups, and the differentials are given component-wise by residue and corestriction homomorphisms. The p th homology group of this complex, i.e., homology at the middle term above, is denoted A p (X, K q ), and classical Chow groups in the sense of [Ful] are recovered via the identification CH p (X) = A p (X, K −p ). The study of these K-cohomology groups for homogenous varieties has seen many useful applications to Galois cohomology, and significant results include the Merkurjev-Suslin Theorem [MS82] and the Milnor and Bloch-Kato Conjectures [Voe/ℓ]. Unfortunately, general descriptions of these groups remain elusive, and computations are done in various cases, described below.Algebraic cycles have also found a great deal of utility in the study of algebraic groups. In [CM01], Chernousov and Merkurjev show that for certain groups G and 2010 Mathematics Subject Classification. Primary 14C25, Secondary 16K20.