The subject beetle is probably 3-4mm in length. Camera is a Canon EOS 700D with a standard 200mm zoom lens and a 40mm lens spacer
I have one of these too! I bought it with the other things in my macro attachments. Very compact and cheap bit of kit. It produces an ultra short DOF so it's only good if I'm capturing something on a flat plane using a tripod or if I end up doing focus stacking like I've been discussing with another commenter