I bought my secondhand Ranger from ebay and I am very happy with the purchase. The previous owner told me that BCD is four year old now but its condition is still immaculate. Last week I went for diving with a friend who has also a one year old Ranger and I have noticed that his BCD has two dump valves (i hope this is what they are called) and that is has the rear trim weight pockets as standard. Are there any other differences and are they that important? Apart from rear trim pockets, can I upgrade mine (retrofit more dump valves)? When the change in model occured? By the way I dove down to 61 feet as part of my AOW and the BCD was excellent.