18" x 40" replacement brine tank for water softeners Complete tank with safety float and air check Safety float prevents overfilling Easy to install and begin using with your water filter We have a great selection of Brine Tanks products including the Complete 18" x 40" Brine Tank With 2310 Safety Float (BT1840R-B2310) at unbeatable prices.18" x 40" brine tank complete with 2310 brine valve (float) 4" brine well and cover.