15 w laser is likely a pulsed laser. Diodes don't really get that powerful. It means it's 15 watts a pulse, but it can't deliver it constantly. i have one also but ithis laser have not more power then the 2,5 w laser i think the 7,5w laser from laseraxe have more power then this pulsed 15 w laser.

Model Number: TGLEISER-B15W Focal length: Can adjust

Laser Beam: Focusalbe Beam, Collimated Beam

Wavelength: 445nm-450nm

Output Power: 15W pulsed

                        Average 8W (Max) Operating Voltage: DC 12V

Working Current: <4A

Operation mode: pulsed laser 100 ns Duty 50%,

                              With TTL modulation/ Analog modulation