$55.99 Pentel EnerGel RTX Gel Pen, 0.7mm Medium Metal Tip, Blue Ink - Walmart.com
Aliexpress.com : Buy Wholesale Price 3 different colors 0.5mm Gel Pens Refill 2.65mm inner 
EnerGel Deluxe RTX Retractable Pens - 0.3 mm Pen Point Size - Refillable - Blue Gel-based Ink 
