The e-cig is sharper than the background. Needs grain to match. (a good plugin to use is GrainSurgery/Realgrain)
Note the lens blur near the edges of the image, the e-cig should follow suit.
The right hand side end needs some perspective/curvature.
The screw as drawn is not really a screw, just rings, you will not be able to twist it into the other piece.
The LOGIC logo needs to follow the curve.
I don't understand the thing light stripes on the long piece.
The edge between the blue end and the black tube looks too generic, needs a little groove. The black curve should be an ellipse with the large diameter equal to the e-cig width, currently looks like a part of a large circle.
of the same model show the 'filter' part to be slightly larger diameter and the ring where the two pieces connect is shinier.