Model: X5,
No battery (Powered by 2*AAA). Level bubble *1
Model: X6-no-charge.
No battery (Powered by 3*AAA). Electronic angle sensor, function for measure angle.
Model: X6-Rechargeable.
Rechargeable battery(Powered by 3*AAA).Electronic angle sensor, function for measure angle.
Model 1: X6-no-chargeable.
Model 2 : X5