A drip irrigation emitter may be provided with a coupler (125) for bonding to an inner surface (123) of a conduit. The emitter may include for example a button flow restrictor (128). The coupler (125) may optionally provide an outlet zone on the conduit surface that is large enough for automated perforation. Bonding the emitter to the surface of the conduit may have a minimal effect on the dimensions and/or properties of the conduit. A button drip irrigation emitter may optionally include a two part labyrinth (232). The labyrinth (232) may for example be confined between a cylindrical outer surface (230) and a cover (252) and/or wind between intermeshing baffles (284, 286) on the cover (252) and/or the surface (230).
