z fins slalom slm menegattiDelivery times: Unfortunately, all custom Fins have extended delivery times due to production bottlenecks. We are in direct contact with the manufacturer and can therefore guarantee the fastest possible delivery. However, in some cases, delivery may take up to 1 4 months. Introducing the Slalom SLM fin. SLM is similar to SL. The difference lies in the profile, which is adapted for rougher conditions to provide consistent lift even in rough water.