BASS Overdrive CP-65, it includes TONE, GAIN, VOL, SHAPE controls. 

SHAPE controls gives your bass more attack. 

With boost effect 

Features:

1. True Bypass design, with aluminum alloy casing 

2. Power Requirement: 9V DC center negative 

3. Current consumption: 30mA

4. Product Dimensions: 11.2x6.4x3.4cm

5. Weight:0.23kg