Plane with no stall warning device?

..

GLIDERS

Gliders use no mechanical nor electric stall warning devices.

They use the glider.

By feeling the air, feeling control response, remaining cognizant of
roll pitch and yaw attitudes relative to airpeed, watching airspeed,
feeling g forces; watching horizon, watching changing clouds, birds,
smoke, sun angle, wind shadow on water, other aircraft, ground,
terrain features and all outside glider;
keeping glider in coordinated flight by centering yaw string on
front center of canopy, listening, feeling, dancing on clouds, to
keep flying they keep flying, generally without stall.

It is blessed to not have a stall horn aboard.

Gliders often have stick w/elevator trim, ailerons, rudder operated by
adjustable pedals, spoilers or dive brakes, many have manually
operated flaps with positive and negative position settings for climb
cruise and fast running, retractable landing gear, disposable water
ballast, 12 vdc battery elec systems, flight computers linked to gps
maps and sensitive rate of climb indicators w/adjustable sound.
Gliders are usually configured as inline two seaters for training, or
supine single seaters with long plexi canopy for personal use
including glider racing or cross country flying. Modern high
performance gliders are made of glass composite fiber materials
(reinforced plastics).

Thereupon one finds a plane without a stall horn.