CREATE TABLE table_52891 ("Maker" CLOB, "Model" CLOB, "Intro year" CLOB, "Screen size  ( inch ) " CLOB, "Self-lit" CLOB, "Screen type" CLOB, "Weight" CLOB, "Screen pixels" CLOB, "Touch screen" CLOB, "micro SDHC" CLOB)

For Amazon.com's device with a weight of 221g (7.8oz) how many screen pixels does the device have?
SELECT "Screen pixels" FROM table_52891 WHERE "Maker" = 'amazon.com' AND "Weight" = '221g (7.8oz)'
SELECT "Screen pixels" FROM "table_52891" WHERE "Maker" = 'amazon.com' AND "Weight" = '221g (7.8oz)'