Due to the UK being shut off from the European mainland because of the new Covid-19 mutation it is very likely your order will be delayed until further notice. There is nothing we can do about this at this point in time
Named after its inventor, the English mathematician and physicist Peter Barlow, the Barlow lens is a diverging (negative) lens, which is used to increase the effective focal length. This results in a higher magnification. Moreover, the Barlow lens is very easy to use as the Barlow lens can be placed directly in front of the eyepiece.
Imagine you use a 10mm eyepiece with the focal point of your telescope being 1000mm. Now you have a standard magnification of 100x. With a 3x Barlow lens you will arrive at magnification of 300 x! This is a cost-effective way to achieve a better result. An additional advantage is the ‘flatter’ and sharper image produced by the Barlow lens. A minor drawback is the small optic angle inherent in higher magnifications.