There's a few sizes, these are for the 4mm-ish flat ends. Black ones.
Traditional Scottish Bagpipe in Plain Black – Perfect for Beginners and Professionals
Plain Black Rotary Encoder Control Knob - 6mm D-Shaft Hole - Push Fit
Smooth Side Plain Black Control Knob 6mm Splined Hole
Perri's PLAIN BLACK 2" Wide Poly Webbing Guitar Strap - Fully Adjustable
Plain Black Guitar Gig Bag – Basic Water-Resistant Soft Case for Electric Guitar
Rico Tenor / Baritone Sling Jazz Plain Black
