Long history of performance Considered the standard for power and durability since 1965. Proven vented design Decreases drag on the upstroke; enhances thrust on the downstroke. Adjustable heel strap Secures strap for ease of pre-dive preparation. Specification Sizes: Medium UK 7-8 Large UK9-10 Extra Large UK11-12 Extra Extra Large above UK12 Note: If using with drysuit boots select a size larger than indicated