How you select spindle lock will vary depending on the make and model of your cordless screwdriver.
The spindle lock feature on this cordless screwdriver is selected using the forward/reverse switch on the top of the tool.
Sliding the switch to the left displays a forward-facing triangle, meaning that the screwdriver is turning the bit in a forwards direction (clockwise).
This is used for inserting screws.
Sliding the switch to the right displays a backward-facing triangle, meaning that the screwdriver is in reverse, and will turn the bit backwards (anti-clockwise).
This is used for removing screws.
Sliding the switch into the centre so no triangles are displayed means that spindle lock has been selected, and the bit will not rotate