You might not use a cross laser often, but it's very handy to have your own once the need arises. There's no cord to restrict you, just make sure you've charged the battery.
From ManoMano
0601066N00 gpl 3 g Professional Point Laser BSH601066N00 - Bosch
Conrad Electronic
Bosch Professional GPL 3 G Plump dot laser Incl. bag Range (max.): 30 m
This product is also available at 3 unverified stores.