I.V. extension tube in flexible, transparent polyurethane tubing with Vadsite and flat clamp. Octopus with Vadsite is a multi-purpose catheter accessory, a single lumen or multi-lumen I.V. extension tube with needleless connector(s), enabling intermittent injections or continuous infusions of fluids or medications and blood sampling depending on device variant. The variants with anti-reflux valves negate the risk of backtracking (retrogate flow) of infusate and thus the risk of overmedication (drug overdose). It is not possible to withdraw blood/fluid via an octopus where the lumen features an anti-reflux valve.