I'm looking for an accessible reference for the definition of the fundamental class in equivariant K-theory.

The setup I'm interested in is the following: suppose $V$ is a vector space equipped with the $G$-action and $M \subset V$ is a closed $G$-invariant subvariety. From the equivariant cohomology point of view, the equivariant Poincare dual of $M$ is the class in $$\operatorname{eP}(M)\in H_G^* (pt).$$

Can the K-theoretic fundamental class of $M$ be described as a class in $K_G (pt)\cong R(G)?$ And if yes, then how is it defined?