Speedo Bm Logo Muscle back Swimsuit Ladies This Speedo Bm Logo Muscle back Swimsuit is great for finding your lane. Crafted from a polyester material in a regular fit, this piece includes chlorine resistant Endurance Plus technology to boost its durability, whilst a 4-way stretch fabric allows for ease of movement in the pool. Finished with areas of separate coloured trim and the Speedo branding for instant recognition.