Currently, Elkhart RV Parts does not have the Dometic 834EV17.400 awning roller tube in stock. However, we are happy to assist in locating a suitable equivalent or compatible replacement for your 2007 Cougar 278RKS. Providing additional awning details such as length or fabric color can help us narrow down options. Once we identify available replacements, we will share pricing and ordering information. You can also use promo code ALIRVP to receive $5 off your order.