2 different sizes.
Heat development up to 10 hours (in combination with a 1800BT).
Batteries can be charged with USB.
size: waist 70-90 cm
size: waist 90-130 cm.
Contents of the package
2x lithium pack 1200BT (you can also choose the 1800BT series, this is more powerful)
1x USB charger 100-240 V
1x Lenz heat connection 1.0