UW300

It's a Boss AW-2 copy . Like all other Behringer pedals , they sound like original boss or better . And cost a third or less . I use it with a fender jazz bass . Put all knobs at zero except sensitivity at one quarter . Then you have a very good Autowah , clean , musical , but loose volume and low frequency punch . Have to mix it with dry signal somehow . I use a Boss LS-2 as mixer but you can use effect loop on the Amp .    

I think Behringer pedals are good . They're plastic but strong enough for any use .

Not easy at first , at least for bass . Not good if you start with all settings centered . start from all settings at zero level .

they reply only to easy questions

I play rock , R&B , funk , some jazz ... i don't think effects are important for bass , but sometimes you can have fun with them . Just remember that almost ALL effects try to make you loose low frequencies and punch , so find a way to correct that . This effect is no exception : you need to use it together with low boost , dry signal mix , maybe a chorus ... to keep your sound strong enough