These are Miller Industries Control Handle Knobs. They are offered in Blue (12-0311699), Red (12-0311700), Green (12-0311701) and Gray (12-0311702).
Features:
2-1/4" Long
Available Colors: Blue, Red, Green, Gray
Screws into the control rod
Fits:
Century LCG 12 Series Steel & Aluminum Carriers 2009-Current
Century LCG 16 Series Steel & Aluminum Carriers 2009-2014
Century LCG Generation II 16 Series Steel & Aluminum Carriers 2014-Current
Century 10 Series Steel & Aluminum Carriers 2005-Current