DISCLAIMER:- PLEASE NOTE THAT THIS ITEM WAS DESIGNED AND MANUFACTURED BY ME. . THIS IS NOT A GENUINE PART PRODUCED BY THE Air Arms COMPANY.   Brand New 3D Printed Air Arms S410 Valve Cap. Srews on as a replacement for lost or damaged cap or just to bling things up. It has an extended thumb srew for ease of fitting.Thses are pretty strong but please do not over tighten them or it may cause damage to the part. Dimentions - L 50mm x Dia 31mm  aprox Please note the Glow In the Dark one is whitish translusant until it is exposed to strong light then it glows bright fluresent Green in the Dark.