1) Large capacity range from 5L to 20L is optional

2) Double ignition pin, automatic electrical pulse ignition device

3) Flame failure safety device is optional.

4) Over water pressure protection device.

5) Water-gas interlock valve device

6) Anti-dry combustion protection device.

7) Winter-summer switch option for gas saving

8) Anti-freezing device

9) Free hand shower

10) ODS device is optional

11) 20-minute timer is optional

12) Zero water pres sure start for all capacity is optional

13) The faceplate shapes are optional.

14) Liquid crystal display (LCD) is optional.

15)The competitive price is optional according to material collocation.