Cubit 15.7 User Documentation
The reflect command mirrors the body about a plane normal to the vector supplied. The reflect command will destroy the existing body and replace it with the new reflected body, unless the copy option is used.
{Body|Volume|Surface|Curve|Vertex|Group} <range> [Copy] Reflect <x-comp> <y-comp> <z-comp>
{Body|Volume|Surface|Curve|Vertex|Group} <range> [Copy] Reflect {X|Y|Z}