Built by Daystate for RWS along with the RWS Series 50 and a forerunner to the Daystate Air Ranger. Fitted with a 500cc bottle and a regulator designed by Joe Korick (adapted by Daystate to work in the vertical position). Initially came in either a walnut or green synthetic stock and later available in black synthetic. 500+ because at 12ftlbs it was supposedly capable of 500+ shots from one fill in .22 calibre (350 shots in .177 calibre). Came with a bipod and a case. However, the rifle wouldn't fit the case with a moderator fitted. Quite expensive at the time at £800.00, (I've just found the receipt and handbook for mine)
I bought one new with the black synthetic stock in January 2005 and it is the most accurate .22 rifle I have owned, very underrated in my opinion. If it needs a service Staffordshire Custom Rifles can do it at a reasonable cost