Yamadai Games customizes his HK416 airsoft rifle with three tactical items purchased from Amazon: a sling mount, a foregrip, and a holographic-style dot sight. He demonstrates the installation and functionality of each item, expressing satisfaction with the solid construction of the sling mount and the overall aesthetic of the dot sight, despite its dimness. The foregrip, however, was an accidental duplicate purchase. The video concludes with a test of the rifle, confirming the sight's adjustability and recommending the affordable gear for airsoft players who prioritize appearance over top-tier performance.