#4-40×1/2in Yellow Zinc Standoff, M/M, 1/4in threaded ends $0.50 #4-40 x 1/2″ yellow zinc coated (chromate) steel standoff.
	IR Reflector sensor with leads $1.00 Reflective optical sensor with transistor output.
	44mm Piezo Speaker $2.25 For making a LOUD beep, this piezo suits your need. Comes mounted in a plastic case with mounting tabs.
	Maxell LR44 A76 Alkaline Battery $0.95 These LR44 button cell batteries are fairly common but it can be hard to keep them around. They fit the digital calipers, so if you use yours as much as we use ours, you may want to go ahead and pick up a spare.
	eSun 1.75mm PETG filament – Yellow – 1kg Spool $30.00 1.75mm PETG filament for 3D printing. PETG is a new material that is strong and slightly flexible like ABS while being easy to print like PLA. Stunning transparent yellow finish.