If you're not familiar, an attenuator is used to make your amp act like it's turned up loud at low volumes. It goes between your amp and speaker. Weber ones are well regarded, so it's a pretty safe bet. Unlike other Weber products, it won't cook your dinner.

Model: Weber Mini Mass Speaker Attenuator 50w
Made: USA, recent model 
Type: power soak/attenuator
Power: passive, 9v DC input for footswitch
Equivalent new street price (approx): n/a
Mods: none
Accessories: no box or manual
Condition notes: used, no major marks, fully functional. Overall: very good condition