Electric Heating Pad - 10cm x 5cm

This is hot! Literally! Apply 5-12VDC and the stainless steel fibers in this heating fabric will warm up, creating a little heating pad.
On one hand, it's just a gigantic resistor. On the other hand, it's flexible, light, and can be wrapped around a project. Originally designed for portable wearable heating pads, this fabric can be used for wearables, weather balloons, diy-bio projects, thermal cycling for materials testing, etc.
The temperature reached varies with voltage. This piece is ~ 10cm long, so look in the spec sheets in the Technical Details tab for a table of voltage/current/temperature outputs. You could PWM it with a power N-channel transistor if you want to have finer temperature control.
TECHNICAL DETAILS

Dimensions: 110.65mm / 4.35" x 70.45mm / 2.77" x 1.54mm / 0.06"
Wire Length: 35.8mm / 1.4"
Weight: 2.53g
Insulation: Polyimide film ('Kapton')
Fabric made of Polyester filament and micro stainless steel fiber
Power requirements: 5V DC up to 1A
Spec sheet #1
Spec sheet #2