As stated at the Lazertoyz site
http://www.ncweb.com/biz/dan/Receivers.html
VamPower single conversion crystals:
These crystals are single conversion crystals. They are best suited to our VPRS410 and VPRS610 single conversion receivers, though they will work with other receivers such as GWS receivers.
Does this mean that GWS crystals can also work in the VamPower receivers?