The Chelsea Bra was drafted for use with the Contour Atelier Full-Cup Underwires. The wire chart is included with the Pattern files and can also be download here
Additionally, you can use wires from the following suppliers: *
Round wires (Emerald Erin - Canada)
Round wires (Nellie Jones - New Zealand)
Regular / Classic Bra Underwire (Madalynne Intimates - USA)
R1 Regular Day wires (The Bra Makery - USA)
Flexible wires (Bra Builders - USA)
*before ordering wires, make sure to compare the wire charts against the one supplied with this pattern. You may need to go up or down a size, for example the Emerald Erin size 38 wire matches the Contour Atelier size 36 wire.