Rockboard Natural Sound Buffer

Prevents signal loss in signal chains
Input: 6.3 mm mono jack
Output: 6.3 mm mono jack
Robust metal housing
Front side power supply connection
Operation with 9 V battery or power supply (not included, matching power supply: Art. 409939)
Dimensions (W x D x H): 58 x 89 x 32 mm
Weight: 92 g

https://www.thomann.de/gb/rockboard_natural_sound_buffer.htm