These worked great for me with all three of my kids, mounted them at the top of the door.

National Hardware N238-972 V800 Sliding Door Latch in Nickel https://www.amazon.com/dp/B000FPAJ8S/ref=cm_sw_r_cp_api_i_Y8X87Q8KXK9CX51TC3CJ?_encoding=UTF8&psc=1