I have an Adorama screw on lens cap for every lens I own. They are more durable than the factory issued ones and they do not fall off. In addition, I can remove the lens hoods without removing the lens cap. When it's time to shoot, just unscrew the cap, stick it in your back pocket and go. I can also recomment the Adorama screw-in filter covers. They are made with the same durable construction and are ideal for stacking filters in your gadget bag. All of my filters are B+W and the metal lens cap very nicely protects the investment in filters I have made to protect my investment in the lens itself. They look great too.