From Made My Wardrobe:
The Lottie Top and Bra is your classic sporty base layer. It has a flattering racerback shape and can be made full length or as a bra with elasticated underband. The bra is not underwired but does provide a lovely amount of support across sizes.
Recommended fabrics: Medium weight knit fabrics such as cotton, viscose or polyester jersey, scuba or lycra. Your fabric must have a two-way stretch.
Sizes: UK 6 - 24